[qbunnie]

MMS is NOT included as part of the WM6.1. At least not on Sprint. I've run several variations of WM6.1, both custom and the official beta, and not one of them has MMS built in like you want. Sprint IS working on a solution, but as cj10488 has mentioned, it will come out by itself, NOT as part of a new ROM. Timeframe for that is in the summer, after the new ROM officially drops in mid July.
Also, sMMS is a fantastic program. It is a 3rd party program, but one of the best I've seen, give Sprint's MMS limitations. It was entirely designed for the problems you just describe a few posts ago. It is free for partial use, and a $5 paypal donation gets you features like an inbox for you pictures. The interface is great, you should really look into it. Its stickied in the software thread.