Fred's a lock at this point. Unfortunately, as good as Fitz has been, QB is always a tough position. Hasselbeck and Schaub might give him a run for his money in the AFC (Brady's a given, though he doesn't always play). Luckily the AFC has fewer good QBs than the NFC.
After yesterday's game, Wilson's got to be under consideration if his play continues at this level. Barnett's probably as close to a lock on D as we've got, partly from the fact that he is known from his time in GB and because he's among the league leaders in tackles. Someone from the secondary probably deserves to be there due to all the INTs, though to some extent some of that can be attributed to the pressure the line and the LBs have gotten on opposing QBs despite the lack of sacks. So who knows.
If Stevie steps up his game a bit, he might work his way in, but at this point he's been too quiet in the last couple of weeks.
Possibly an O-liner - at this point someone on the line deserves to be there considering they've given up the fewest sacks in the league and Jackson's run so well.