[army] i'm going to MEPS tomorrow...question about the DEP?

No you are not obligated to the Army. I went to MEPS in June 1992, was put in DEP, and shipped in December. I attended exactly 0 DEP meetings. They are voluntary. They would probably help if you went though, just to get ready for basic. You are not officially in the Army until you take the oath, which is just before leaving for basic. I'm not 100% sure but you could probably get out of going if you changed your mind, even after going to MEPS the first time.