I'm running 3 sessions on my 2 year old 20" imac (4gb 2.4C2D, HD2600). I've previously run 4 but 5 kills it. With 3 Dalaran is still painful but nothing else is much of a problem. I'm waiting to see what the MBP refreshes are like and hoping to expand out to 5 boxing, either with a MBP or *fingers crossed* with some network support. Failing that I'm going to look at something beefier hardware wise. but I wanted this machine to last me 3 years when I bought it (before getting into multiboxing) and its perfectly good for everything else I need.

I run an extra monitor for the slaves and browsers and am using a Razor Naga for some extra keys which I like a lot.