The 2011 WHS does not support the drive extender technology that made WHS v1 so accommodating. Just toss another drive into the pool and it would be added to the total drive space. JBOD at its finest. A clear division arose in the WHS community between old version users who demanded drive extender support and guys who just wanted the newer OS and not too concerned with drive extender. Funny thing is, Windows 8 now has drive extender technology built right into it !!!
Stupid MS ... I mean, I want to buy your stuff, but sometimes you vex me so and try my patience.
So in conclusion, if you only have one HD in your desktop to be re-purposed as a WHS, it doesn't affect you to buy the 2011 version and use that.
Intel i5 2500K@4.3, Gigabyte Z68XP-UD3-iSSD, Powercolor 7970 3GB, 2GB Hitachi HDD, Thermaltake Level 10 GT Snow Ed, Corsair H80, Win 7 Pro