We all know Doc is going to shorten the rotation for the playoffs. I think the roster as currently constituted presents some challenges, even if healthy.
PG: Rondo. Backed up by Marbury. This one is easy. I don't think they brought Marbury in to sit, and he'll be needed for his ballhandling against pressure. House might occasionally play the PG situationally, when another shooter is needed on the court with the Big 3.
Wings: R. Allen and Pierce. But who backs them up? House will obviously see minutes here, apparently paired with Marbury in the backcourt. After that it's a tough one. T. Allen may not be healthy and, even if he is, do we want him playing in the playoffs? Scal's situation is scary with the concussions - I'm not sure if he should try to come back this year. Doc's shown that he will occasionaly play Marbury with Rondo on the floor, but that doesn't solve the size problem on the wing. That leaves Walker who I'm sure Doc won't play in the playoffs (rookie). So, I'm thinking House plays the bulk of the backup minutes here, with Doc regularly using the 3 guard lineup where R. Allen plays the "SF." This is not ideal, and is a real weakness right now.
Bigs: KG and Perk. I think Doc uses the backup bigs, Powe, Baby, and Moore, situationally. While Moore does provide length, activity, and athleticism, he's not a good shotblocker and does not appear strong on the boards. He's also horribly foul-prone for a veteran. Because of that, I still think we'll see some of the Powe/Baby frontcourt when Doc feels Baby can handle the other team's center. Obviously all 3 are inconsistent so Doc's juggling of their minutes to find the right combinations will be a real challenge.
In sum, I see Marbury and House off the bench getting regular minutes, with Doc using Powe, Baby, and Moore in a haphazard fashion based on matchups. Clearly the backup SF is the big weakness in the rotation. Hopefully, R. Allen, Pierce and House can form a three-man rotation on the wings without R. Allen getting abused on defense when he's playing the SF (he seems to do allright, for the most part). T. Allen is the wild card and it's tough to know whether Doc will (or should) trust him to play meaningful minutes in the playoffs.