the ata raid motherboards that are coming out recently have 2 additional ide ports on it so that you can set up usually 2 type of raid. Drive stripping which will turn 2 identical drives into 1 drive of double the size i.e. 2 20 gugs into 1 faster 40 gig. And drive mirroring that will mirror your main drive so that if you have a hard drive crash all your stuff is backed up. The other thing you can do is usually you can turn the raid off and just use it as regular ata ports in which case you can have 8 total ide devices in your system.
As for the motherboards i have no clue...i am an asus man been using them for awhile with no probs..havent heard to much about ABit though.
On a side note all you tech geeks like me would love where i live i live in silicon valley in a town called fremont, california and i am surrounded by all sorts of computers plants Creative AMD Intel ECS Tyan Asus its a beautiful area =P, you cant throw a stone without hitting one =)
and if your looking for a new motherboard go with asus's new one a7v333 i believe has built on raid/usb 2.0/firewire...its ata133 and uses the new ddr memory coming out. lol and for you customizers out there it comes with a utility that allows you to edit the bios flash screen =)