I've been wanting to jump into the Mac scene for awhile now, and these new iMacs are exactly the excuse I've been needing to force myself to do it. An iMac with a dual-core Intel chip? Man, two years ago that would have been unthinkable.
Well, I'm declaring it done, although it's failing in the kindest, gentlest fashion I've ever seen from unhappy hardware. :-) Power up the machine & the tray opens. Close the tray, it thinks a moment, then opens the tray. Repeatedly.