They will, that's the justification for the 60 vote supermajority threshold for passing. 60 Senators can walk over up to 40 who withhold consent to limit debate.
No fillibuster they changed the rule back in Jan.
Now:
http://blogs.rollcall.com/wgdb/debt-limit-deal-could-test-new-floor-procedure/
Eliminates the right to filibuster a motion to proceed if the majority leader permits up to four amendment votes.
If the majority leader wants to bring up a bill, he can get a vote to do so four hours after he files a motion to proceed.
At least two amendments from the majority and two from the minority must be allowed.
If one of the first four amendments isn’t germane to the bill, it will be subject to a 60-vote threshold for passage.
It’s clear sailing in the senate. Mitch gets to put two (embarassing to Democrats) amendments to a vote then off it goes to the House.