It too about an hour, once I'd rebooted, I discovered thet the line "add a new Mac to you Mac" isn't just advertsiing puff – it genuinely does feel like a new machine. The visual aesthetic of the new OS is markedly different from previous interations, giving the interface a new, pleasingly solid feel. CoverFlow for documents is just terrific, and Quicklook (whereby you can hit the space bar while selecting a document, and open a detailed preview without having to open the actual application) is shaping up to be one of those "how did I live without it?" features.
And, most importantly, World of Warcraft runs just fine.
All good, so far.