I'll start off simply stating that given the current state of the PC (or Mac if semantics really matter that much to you) and each
main-stream OS (including your major Linux distributions) available for implementation is a problem.
Extending this argument even further along with some Alan Kaye rhetoric, I'd be willing to go out on a limb and say that personal computing is even a bigger problem and quite possibly a super-set or, for the lack of better words, a more general characterization of the previous problem stated.
I think Virtualization is important since it is the only foreseeable solution of bridging the gap between the way we think about the web, software, firmware, hardware, etc. which, IMO, would lead to an evolution in the way we think and create user environments.
