Depends on who you would be dropping for a 3rd QB, but I don't think I would do it.
I'd be dropping James Davis.
My Roster is below. We only start 1 QB, but we weigh them rather heavily in my league, so...
I'm leaning Cassell over Collins(who had a good report today)
12 team, PPR, 6pt per TD for all, re-draft league:
QB: Donovan McNabb
RB: Maurice Jones-Drew
RB: Brandon Jacobs
WR: Roddy White
WR: Donnie Avery
WR/RB: Donald Driver
TE: Visanthe Shiancoe
K: Nick Folk
QB: Carson Palmer
RB's: Chester Taylor, Fred Jackson, Laurence Maroney,
James Davis, Mike Bell
WR's: Earl Bennett
Roster: 1Qb, 2Rb, 2Wr, 1Rb/Wr flx, 1Te, 1K,1D
1/2pt for QB Completion, 1/4 PPrush
12 team league