Wow.. NVidia just introduced Fermi. I like the name better than Tesla because of national bias ;)
The comparison with Larrabee is somewhat obvious, though my understanding is that Larrabee starts as a consumer product, while Fermi starts as an high-end number crunching solution.
The Larrabee seems like it would be more easy to program.. however the recent demoing at IDF didn't really impress anyone.
Also, NVidia is talking about cozy source code debugger integrated in Visual Studio, and even support for C++ (though I assume that for parallelism one still has to use some extensions quite wisely).
Interestingly, either way, it seems that nobody's final goal is really the PC. The important thing is to have your GPGPU chip in a console and then one for business machines.. while most PC games are going to be pushing less and less polygons.. so I'm told, but I wouldn't know, because I was never a PC gamer.