In all likelihood the Giants will be bringing in new O-linemen next season. Baas has not done consistently well. They made an investment in him but it is always possible that he could be cut.
What I'd like to see happen next year is if no free agent linemen are brought in, I'd fully expect the Giants to make it a priority to draft O-line. The question is what can we expect this O-line to look like next year? In all likelihood rookies brought in may not be starting right away. If someone knows a can't miss guy coming out that can start right away, please mention him in this thread and project how the line will look.
It is possible Baas may move to Guard as that is his natural position and perhaps he'd thrive there. Diehl is likely not going anywhere but K-Mac is a free agent and I just don't think they'll resign him this time around as he is just not as solid as he once was. Snee is also a lock to stay especially if Coughlin stays. I know much depends on the coaching staff and what may occur but all else being equal, here's what I think:
Left Tackle: Beatty
Left Guard: Boothe or Baas (Petrus is the wildcard though)
Center: Boothe if Baas goes to Guard or a new guy entirely if Baas is gone
Right Guard: Snee
Right Tackle: Diehl (until Brewer or another rookie is ready)