Well, it only has 2GB of RAM for now. There's also 896MB of video RAM on top of that. As soon as DDR3 is a bit more affordable, it will go up to at least 4GB.
The only hassle I have had so far is this one 32-bit application.
Finally, 64-bit is the way forward, generally. Aside from losing the 4G limit, the AMD64 instruction set is better, there are more registers for the compiler to play with.
In short, why not?