stay in for a few more years if you can.. otherwise.. get educated... document all your ailments for the VA benefits.
^^^ x 100. Can't emphasize that enough.
- Stay in if possible. Getting that pension check is a nice relief after you've just been laid off.
- Get educated as much as possible beforehand. Use that 9/11 GI Bill.
- Start looking for a job now. It's never too early to start networking. The job market still sucks even though Obama says everything is great. Don't expect anything special because you're former military.
- Document EVERYTHING medically. Make copies of your medical record because it will invariably get "lost" (mine's been lost 3 times so far). You'd surprised how much disability you may get.