The immediate impact of this decision will be to return the Court to the political balance it had before Justice Scalia's untimely death. The Court will shortly consist of four liberals (Bryer, Sotomayor, Ginsburg, and Kagan), four conservatives (Roberts, Thomas, Alito, and Gorsuch) and one swing vote - Kennedy.
For obvious reasons the Court functions better with an odd number of justices. Operating with eight justices, 4-4 deadlocks gave too much power to lower courts.
----------Looking to the future, today's change in Senate rules will assure that future justices can be approved with a bare majority. Over time, probably a decade or so, the Court will become even more clearly political as whichever party controls the Senate and the White House will select people clearly representing their ideological view of the law and human rights.
I predict it will be long time before any justice will be considered, much less approved, while one party controls the Senate and the other has the White House. Expect some eight and even seven member Courts whenever split control exists, as it did for the last two Obama years. Eventually Presidents facing a Senate controlled by the other party will not bother nominating replacement justices.
We are in an era when Congress is often gridlocked but the Court decides, and in effect legislates. We have just seen the importance of a single party controlling both White House and Senate escalate dramatically. I have to wonder if the importance of the House will decline as a consequence.