Larrabee, we hardly knew ye
Intel has announced that Larrabee, the multi-core AMD and NVidia GPU killer, has been canceled. While Larrabee research lives on and we might see it re-emerge in some form in the future, it won't be any time soon.
Larrabee was appealing to developers because it used a standard x86 instruction set plus some additional vector processing units and a conventional memory architecture. In theory, this should be easier to program than CUDA or Cell because of its familiarity to programmers, generous memory sizes, and fast pathways to get data in and out of the chip.
Another project at Intel, called the Single chip Cloud Computer (SCC), is similar to Larrabee in that it uses an array of simple x86 processors. However SCC uses a mesh router network instead of Larrabee's ring, and appears to be targeted towards running cluster applications (currently coded with MPI and run on commodity Linux servers) instead of SIMD applications (currently coded with threads or chip-specific APIs like CUDA).
Intel would like developers to use architecture-neutral languages like Ct in order to exploit the vectorization capabilities in current Intel chips and get ready for many-core hardware in the future. Ct is not yet in public beta, though there was a similar product available from RapidMind before Intel bought them and folded them into Ct. Ct takes an algorithm written in C++ templates, translates it to an intermediate format, and compiles that format at run time to best use whatever hardware you have. It works best, of course, on Intel hardware.
Another option for developers is OpenCL, a GPGPU extension of OpenGL. Compatible drivers are only just beginning to appear for ATI and NVidia hardware. It will run code on the GPU, the CPU, or a mixture of CPU and GPU, depending on your hardware.
Of all the options currently available for multi-core programming, the one that appeals to me the most right now is Grand Central Dispatch. It uses nice, clean extensions to the C and Objective-C languages plus some operating system support for system-wide lightweight thread scheduling. GCD has been ported to MacOS X and FreeBSD. Until it is available on Linux and Windows, however, it doesn't have any hope of becoming mainstream.