Supers-computer producers willingly used AMD opteron processors, since they have a good performance due to the system bus hyperTransport. Delay in the release of corrected barcelona versions (B3 stepping) was pretty bad for AMD and but also for server and supers-computer producers. Intel processors ( nehalem generation ) will also use a fast system bus QPI , and this fact attracts supers-computer producers already now.
Intel companies concluded a long-term agreement with important supers-computer producer (Cray). In this case Cray will continue to use AMD processors.
The first supers-computer cray on base of intel processors will appear in 2010-2011. Furthermore, Cray does not exclude the possibility to use larrabee in its supers-computer : they will come out as coprocessors - ( accelerating floating-point calculations for example ) .