i recently got my 2nd SSD.

i now have 2 OCZ Vertex Series Turbo 30GB drives.
the nice thing about the turbo version is the max. read speed of 240MB/s (and write of 145 MB/s) which rivals the X-25 intel series.

at first i was just using 1 of the drives with windows, and the patch.mpq, wotlk.mpq etc symlinked to this drive.
now with the second drive i can have the entire wow folder on it which amazingly improved loadtimes and fps even more.

imo, get 1 big driver (60GB) or 2x 30GB, 1 for windows, and 1 for WoW (with free space to load other heavy singleplayer games on if you want)

link to OCZ drive i use http://www.ocztechnology.com/product...ata_ii_2_5-ssd
this one costs about 140 euro here in holland.