Of course, it only takes 50 votes (plus the tie breaker by the President of the Senate) to pass something; but we, under current rules need 60 votes to get an "up or down vote".
But the filibuster is really a Senate rule and is subject to being changed...
More below the fold
Of course, it takes 67 votes to change the Senate rules. But there is a procedure to get around needing 67 votes; that is the so-called nuclear option:
The Senate has a process in place for amending rules; this process requires a two-thirds  vote. According to Congressional Quarterly, from 1919-1971, there were nine filibusters relating to Rule 22; in each case, there were insufficient votes to invoke cloture.
In 2005, then Senate Majority Leader Bill Frist threatened to end Democratic filibuster of judicial nominees by something called the "nuclear option." It is actually a series of steps designed to bypass the two-thirds vote requirement to change rules: (cite)
1. The Senate moves to vote on a controversial nominee.
2. At least 41 Senators call for filibuster.
3. The Senate Majority Leader raises a point of order, saying debate has gone on long enough and that a vote must be taken within a certain time frame. (Current Senate rules requires a cloture vote at this point.)
4. The Vice President -- acting as presiding officer -- sustains the point of order.
5. A Democratic Senator appeals the decision.
6. A Republican Senator moves to table the motion on the floor (the appeal).
7. This vote - to table the appeal - is procedural and cannot be subjected to a filibuster; it requires only a majority vote (in case of a tie, the Vice President casts the tie-breaking vote).
8. With debate ended, the Senate would vote on the issue at hand; this vote requires only a majority of those voting. The filibuster has effectively been closed with a majority vote instead of a three-fifths vote.
So, what are we "keeping the power dry" for?