Think about what features you want and which you won't use. Most popular mobo manufactureres are equaly reliable, take note of overclocking features if that interests you (Intel offers very poor overclockabilty if at all).
The biggest difference between mobos that support the new C CPU line is their chipset. There's the 865p, 865pe and 875p. The 875 will give you a performance boost by supporting PAT, but mobo makers like Abit have enhanced the 865 chipset to support something like PAT (it's not called that but does mostly the same) so you can get the much cheaper 865 chipset and enjoy 875 performance. 875 also supports registered or ECC RAM (I don't remember which, but it shouldn't concern the average buyer).
Common mobo features are 5.1 sound, firewire, SATA, SATA RAID, IDE RAID, 100mbit Etherenet, 1Gbit Etherenet, onboard VGA, smart overclocking techniques...
I'm a nuclear reactor cooling system programmer, if you see me running, it's probably already too late.