Haddock, Re: One of us is getting their terminology mixed up. To me, www.top500.org isn't about enterprise market, it's about high performance technical computing. These guys don't normally give a monkey's about backwards compatibility, since they write and compile their own software.
Fair enough, but I'm still telling you that there will be plenty of Xeons on the top-500 list for years to come. The number of Xeons this past year should already tell you that the lack of 64-bit flat addressing is not a huge barrier for entry in this market. As long as Xeon remains somewhat performance competitive with Opteron, it will have the advantage of broad OEM support. If you look at the newest entries on the list, you'll see that the vast majority are from the major OEMs.
Fortunately for Opteron, IBM's new sku gives them easier entry into the market, but I don't think the advantage is large enough at this point to warrant immediate adoption. We'll see if this changes.
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