Intel's upcoming Nehalem processors promise a lot, and on the bench have seen some considerable performance improvements over their Penryn predecessors. The CPUs, based around Intel's new LGA1366 socket, will supposedly be available en-masse starting at the end of this year. Three CPUs running at 2.66GHz, 2.93GHz and 3.2GHz will be available, and will operate in boards built around the X58 and ICH10 chipsets.
Intel is still squabbling with Nvidia, and as such it seems unlikely that their platforms will have SLI support by the time they reach market. However, Intel will be able to offer CrossFire support. In the meantime, Intel is still preventing Nvidia from developing a Nehalem platform, so they will most likely be the exclusive vendor for them in the beginning.