For 2011
F1 status: Jan-Sept
H1-B status: Oct-Dec

Should I be filing 1040 or 1040NR?

I know this question has been asked around a lot but a lot of the material is old. Reposting to get latest information.

Thanks in advance.

It depends on how many years you have been here. Up to the fifth year of F1 is nonresident.