Not Positive... But
I am an Active Duty Marine stationed in the National Capital Region. I have read a lot of gouge on both the Navy and Marine Corps side of the house concerning budget cuts. I have not seen anything about the incoming class size being reduce for this, or any subsequent years.
The only cuts currently announced or planned for any Midshipman (USNA or NROTC) are the summer training programs, and even that doesn't specify what the cuts will be. It is safe to assume Summer Cruises will be canceled, however, the Navy still has to do something with them, so we will see.
Further, and this is a belief, and not fact so feel free to chime in if anyone has any further information. I "believe" that the brigade size, not class size, to ALL of the service academies is protected under Title 10 USC. The USNA is set for a Brigade of 4400 Midshipman. The typical incoming class of around 1200 is the 1100 slated, and then enough to make up for those that attrit prior to graduation to set the brigade back at 4400 for the beginning of the shool year.
I know for a fact this is the case for the Reserves, all branches, and I believe holds true for the Service Academies. So, unless USC is rewritten, which is not exactly easy, yet not impossible to do, then the class size will not shrink.
Additionally, the Senior Military Colleges ROTC programs enjoy similiar protection. All other ROTC programs however can be cut by the individual service at their discression, but again, those cuts have not been addressed by the Navy or Marine Corps at this point.