Good point, but surely the raison d'etre for these 890 chipset with AM3+ sockets motherboards is that they're aimed at people who want to build a PC now with a Phenom chip but have an upgrade path to a Zambezi CPU later (ie: me, although I can't be the only one) Otherwise we might as well wait for the 990 boards anyway
It would be interesting to know if there are any other performance differences as it looks like there will be 890 AM3 and AM3+ boards on the shop shelves side by side.
Here's a list of the current MSI AM3 motherboards that have been updated to handle the BD Zambezi CPUs, 3 already are, the rest will follow with a BIOS update. If you have one of these AM3 motherboards you won't need a new motherboard for Bulldozer. http://event.msi.com/mb/am3+/