I understand your frustration, but we would have had same complaints if we had worked on the MMV instead of the ARP2600V, the ARP2600V instead of the CS80V, and so on...
The MMV has reached version 2.2, i.e. the highest version number in Arturia range of synths as of today (AF apart), with a nice level of features and stability, and relatively low resources consuming. Sure it still have some residual bugs, as there will ever be as long as programs are coded by human beings. But you can honestly count on a maintenance update for 2009.
On the other side, Brass was stalled to a pre-VST2.4 version, and we decided to develop a severe upgrade instead of a simple maintenance update. That can be discussed, but that makes sense for us, as it certainly does for Brass users.
I cannot affirm which synthesizers will be updated (maintenance release) or upgraded (update + new features) first; all I know is that 2009 should be rich of events for our trusted and respected users, as well as for ourselves.