It doesn't look like it would require all that much more, if any more, power than Lion does. I have a later 2009 MacBook Pro model right now that works perfectly fine even though I'm sure I would notice a nice difference if I started using a newer Mac (Pro or Air). But while I may get a new Mac this year, I'd rather not feel pressured. Is there any telling at this early point if Mountain Lion will run any slower than Lion does on relatively older Macs? Maybe developers see a detailed enough "recommended specs" list(?), I don't know.