A bit of an update. My BlackBerry did not work, I can think of quite a few reasons why it didn't, but mine should be an isolated case with the exception of not having the BB data service enabled on my account.
However, I am now fully MMS enabled. I called ATT for the second time yesterday and nicely explained the situation with being an iPhone Dev and all. Of course the CSR defaulted to the ATT internal systems saying that OS 2.2.1 is the current OS, blah blah blah, but with kind persistence she tried one more thing. My account was already set to Family Text plan (I did this 2 weeks ago when I first installed Beta 1), so that wasn't the issue. The rep said she wanted to send a quick update to the phone and asked me to power off and back on again. She tweaked something on my account, and boom MMS was working. It was a little like pulling teeth to get her to tell me what she switched, but finally she spilled it. She went into an internal ATT system called "Snoopers" and turned on MMS capabilities. Apparently merely switching your text plan to the family plan and removing the iPhone text option isnt enough. There was this one more switch in "Snoopers" which was required. MMS now works like a charm, short of the occasional (twice since the ATT call) reboot.
does media net have anything to do with this or is it just a snooper thing regardless of media net?