I believe there isn't an install process. But you could always fire up a nightly to test ;)
My guess is this won't see mainstream distribution until they've removed the x86 instruction dependency. I think the shipping version will use LLVM bytecode rather than x86 machine code. (this has been hinted at, too.)
You're probably right about their desire to get rid of the x86 dependency. Distributing LLVM bytecode really is a better way; it'll allow NaCl pages to be viewable on ARM-using devices as well as x86-using PCs without needing to provide separate binaries. As the makers of Android and Chrome OS, Google probably would like to avoid locking ARM out.
My guess is this won't see mainstream distribution until they've removed the x86 instruction dependency. I think the shipping version will use LLVM bytecode rather than x86 machine code. (this has been hinted at, too.)