Three words, LEFT I/O BOARD! Apple hasn't had a logic board span from the left side to the right side of the machine since the early PowerPC days. The MLB is not going to get larger, especially as the enclosure gets thinner; from an engineering standpoint, that makes no sense at all. As for whether or not the Ethernet, FW800 could fit on the machine if it's tapered, they can barely fit on the machine with its current thickness and if it's tapered, it becomes thinner at every point save for the far back of it, so no, even with a left I/I board, it will be cramped. If you'd like, I'd be happy to direct you to the Apple Service Manuals where most of this stuff is apparent. Really, I'd rather educate someone who clearly doesn't know what they're talking about than have a pointless conversation that only further demonstrates how much they don't know what they're talking about.