First off, we talk about the P45R2000-WiFi. In all, it's a board that while having all the bells and whistles you could want, some of them come at a price. This for instance is the dual memory support. While great for the upgraders in us, the placement of the power connectors suffer; not good at all for overclockers.
The other major gripe is that if you want to use eSATA, you have to run two cables from the bottom of the board to the top left of the board. This not only gives you two less SATA ports internally, but again, you're getting more cable clutter. With digital switching readily available, why wasn't this used? - Or better yet, a two port SATA controller to run the eSATA system independently?
Last on the list of complaints is again the lack of digital switching for the PCI Express slots. If you want to use Crossfire, you have to use an old style paddle card that splits the bandwidth.
The P43R1600Twins-WiFi board, while almost a mirror image of the P45R2000-WiFi, it lacks Crossfire support. So this is eliminated for dual GPU users unless you settle on a HD 3870X2 or HD 4870X2 (when it arrives). Next; again due to the dual memory controllers, you lose out on power connector placements. And the routing of the SATA cable to run the single eSATA port means more cable clutter and the loss of one internal SATA port.