I second the EVGA over MSI. Only go with a micro ATX board if for some reason you need to use a small case (e.g. portability, space constraints). Otherwise you can get a lot better cooling with a larger case and overclocking would be easier.
The MSI X58M has an overheating problem with the Northbridge chip! I burned up the first board I tried, with the second one I added a fan tie wrapped to the Northbridge heatsink. This reduced the heatsink temperature from "too hot to touch" to "barely warm" and I have had no trouble with the new board.
I chose the MSI because it was the only board to allow a full complement of RAM (24Gb DDR3) all of the other boards I saw would only run 3Gb DDR3 and the rest would actually be DDR RAM!
Overall I am very happy with the I7/920 and X58M - it benchmarks about 2X faster than the top AMD chip using Poser 7
The other major factor I found was the Operating system - Ubuntu 9.04 64 bit consistently gave 20% faster times over all benchmarks than "Superior" XP64 (a heavily optimised "gamer" build). That corresponds to about 40% better than "stock" (MSDN) XP64 and at least 60% faster than Vista.
Need I add any comments about Firefox 3.5 vs IE 8? See the Mozilla website for much better info than I can repeat here.