Sorry, I should have specified that I wasn't basing my response off of any official information from Apple. I'm fairly confident that it will happen in the near future (although I guess with Apple you never know). I find it hard to believe that they would stick with DVI for the 30", and MDP for the 24", especially since the new MacPros have MDP. The Dual-DVI adapter is just to inelegant a solution from Apple to be more than a temporary solution.
The other option would be do get a different brand 30" monitor (ie, Dell) with a full size display port connection, and use one of the MDP->DP adaptors that are right around the corner (Molex customer support has confirmed to several people that they are making these).