There is nothing to be gained (it will not reduce lag, it will add to it) and a lot ot risks involved (security and other issues).
On top of that, there is no way in hell we will ever run the servers with any type of Windows OS. Never going to happen.
The "cloud" is more gimmick than substance. Marketing seems to be doing its job.
EDIT: Just as a side note. I find it rather comical Microsoft is all about "cloud" computing today. When "cloud" computing was first popular in the mid 80's, Microsoft made a major push towards businesses telling them shared computing environments were not the way to go. Of course they said that because thier OS could not do it. Finally, 25+ years later, they get around to implementing shared server support and they claim its the best thing since sliced bread and the masses fall in line.
Yes, my office, in the early 80's ran a 5 server farm (some days it was 6, sometimes it was 4, no one actually knew the exact count, from day to day, except me), which was completely transparent to the users. They had a context sensitive visual shell to use as well. You could copy and paste between applications as well, all on dumb terminals.
When it comes to shared computing, I have a pretty good handle on the environments it would really work well with.