<< Diffusion, I meant for Sledgehammer (X86-64) not for Itanium. Intel processors always get the support from Microsoft. I'm saying there will never be a native X86-64 implementation of Windows. >>
Much like the Athlon is a RISC core emulating x86 instructions, the sledgehammer is supposed to be a 64 bit RISC chip which emulates a 32 bit x86 chip, thereby getting high speeds at 32 bit apps. Therefore, there will not need to be any new support, other then drivers for chipsets and stuff. Honestly, I would like it if Sun would step in here and kick Intels ass. Sun has 900mhz UltraSPARC III chips with 8mb of cache, and they are supposed to hit 1.4ghz soon, on top of which, the replacement for the E10k is just around the corner, keep in mind that the E10k supports 64 processors, and its replacement supposedly supports 72 chips, and they are UltraSPARC IIIs. If Sun gets its act together, they could gain quite some market share, especially considering their low prices, and the fact that their solutions are more scalable then any thing intel turns out (this side of stuff like their old Paragon supercomputers, dunno what Supers intel makes these days).
Edit: Pardon me, Ultra IIIs have up to 8mb of cache each. You need an 8 way Xeon box to mache the cache of 2 Ultra IIIs.