Is Franken seated?
Current make-up of the Senate is 56 D, 2 Ind (Lieberman and Sanders), 41 R plus one disputed (MN).
Both Lieberman and Sanders caucus with the Democrats and will slavishly vote with them -- giving the D's 58 votes (including Teddy K).
But, to gain cloture, the Dems need 60 votes. Meaning, as you posed, they need at least two R's...plus Kennedy.