I presume you just won't get the battery performance out of x86 version though? Surely it's going to struggle.
It'll be interesting to see if the Surface Pro feels more like an iPaddish-tablet or more like a traditional PC-ish tablet. Unless it's really good at what it does, I think it can easily end up doing more harm than good to Microsoft through Surface brand dilution, consumer confusion (x64 vs ARM, which apps run where), etc.