For all of the melodrama preceding it, Thursday's Senate floor vote to change a ruleand prevent filibusters on certain administration nominees wasn't very dramatic — "people in dark suits milling around on blue carpet," as The Atlantic's Molly Ball put it. Dubbed the "nuclear option" to suggest that the move bore the risk of apocalyptic change, nothing about the 52 to 48 vote seemed, in the moment, all that interesting. What, then, does the change actually mean?
(Aside: If you were hoping for a headline that included "nuclear fallout," there areplenty available.)

It means that President Obama is empowered to pursue his agenda.

The most immediate and obvious effect of the rules change is that it is easier for the Senate's Democratic majority to approve nominees to federal agencies and the judiciary, except for the Supreme Court. Such nominees, like the three Obama nominated to the D.C. Circuit Court of Appeals and whose filibusters were the spur for the rules shift, can no longer be held up by the opposition of 40-or-so senators. To block appointments to courts or federal agencies, Republicans would need 51 votes — a majority.
The approval of those appeals court judges may have significant ramifications down the line. But for the three years remaining in the Obama administration, the change is likely more important for those agency appointments. National Journalpoints out that the president can now assume that his nominees to the Independent Payment Advisory Board will be approved — a body that is responsible for determining how to make Medicare cuts that are a key part of Obamacare. It also means, as The Washington Post notes, that Obama has more flexibility in firing Cabinet members that aren't performing to his standards — after all, a bruising confirmation fight just became much less likely. The Huffington Post notes other effects to that end: the likely confirmation of Janet Yellen to run the Federal Reserve, approval of appointees to the Fed's Board of Governors, the approval of Mel Watt to run the Federal Housing Finance Agency.
At New York Jonathan Chait makes a convincing argument about why this is a significant threat to Obama's opposition.
The main reason for this odd, partial clawback of the filibuster is that President Obama has no real legislative agenda that can pass Congress. At the beginning of the year, it seemed plausible that House Republicans might go along with immigration reform, but even that possibility now looks remote. Nothing can pass.

… President Obama’s second-term agenda runs not through Congress but through his own administrative agencies. … The executive-branch filibuster has become a primary Republican weapon against Obama’s agenda.
Because the House has consistently blocked Senate-passed legislation (such as on immigration) and Senate Republicans have blocked other Obama priorities (such as gun control), the president has explicitly suggested he'll take executive action where possible. That requires actors in the executive branch — people he can now more easily appoint.

It means that Washington just got worse.

This prospect is troublesome to many beyond the Senate Republican caucus. At The New York Times, Jonathan Weisman argues that "over the immediate horizon, the strong-arm move by Senate Democrats ... could usher in an era of rank partisan warfare beyond even what Americans have seen in the past five years" — a truly unsettling prospect.
The Washington Post editorial board suggests that the long-term effects will be harshly negative.
The Democratic action sets a precedent that a future Republican majority will use to change procedures when it gets into a political jam, rather than negotiate with Democrats. The logical outcome is a Senate operating more like the House, with no rights for the minority, no reason for debate and no incentive to cooperate. For those who view that as an improvement, we offer today’s House as a counterargument.
The Post's Dana Milbank goes further, calling the play a "naked power grab," echoing the argument that this means less thoughtful deliberation of the sort upon which the Senate prides itself.

Or it means that Washington just got better.

At Slate, John Dickerson argues that the idea the Senate was some sort of focused, thoughtful body based on deliberation is obviously wrong.
The traditions are still there—senators are not supposed to refer to each other by first name—but as the memories about political slights grow longer than the memories of maintaining time-honored institutional traditions, the place has changed. In part, that's because the keepers of the partisan grudges live throughout the country. The Senate club is much smaller and younger and more receptive to their pressure. Only 32 members of the Senate have served at least three terms, down from 44 just six years ago. More than half of the senators have served one full term or less.
In other words, the idea of the filibuster as a last resort for a gentlemanly orator to raise the strongest sort of objection to his attentive and respectful peers is an ideal that no longer exists in practice.
At The Atlantic, Ta-Nehisi Coates makes the compelling case that facilitating approval of nominees is a good, making appointments a more direct reflection of the election of a chief executive. "Threatening to appoint 'more Scalias and Thomases' [as Iowa Sen. Chuck Grassley threatened] is basically threatening to appoint more judges who would unwaveringly hew to their vision of the country," he writes. "That any political party would like to do this strikes me as unsurprising. The place to decide whether we're going to have 'more Scalias and Thomases' is the ballot box."
Legal expert Andrew Cohen thinks the change will also mean more robust judicial hearings, as senators work to fully vet the nominees that come before them, knowing that they can't subsequently throw up substantial roadblocks. Filibuster reform, he writes, is "rockin' good news."

It means fewer filibusters.

The reform isn't comprehensive, of course. As both the Post and Times graphed the increase in cloture votes — those votes meant to block a filibuster — over time. When cloture became a possibility about a century ago, it was rarely invoked. When the number of votes needed to end a filibuster dropped in the mid-1970s, the practice became more common, spiking with the Republican minority that began at the end of Bush's second term.
While there will still be filibusters on legislation — GovTrack.us indicates there have been 46 cloture votes since January — one category, at least, has been reduced.

It means Trent Lott is sad.

Former Sen. Trent Lott of Mississippi is generally given credit for coining the "nuclear" part of "nuclear option" when Senate Republicans were threatening a similar rules change a decade ago. Now that it's happened, he wishes he never had. The extent to which that opinion is predicated on his being a Republican isn't clear.