Great article. I never seriously considered Amazon until now, and after looking into it I found one important fact not mentioned here. The free trial!
I imagine that there are a number of people in my shoes who are just thinking about getting their feet wet with the cloud. And there is a huge differnce between the trial that Microsoft and Amazon offers. The trial Microsoft offers is absolutely miniscule and makes doing even a simple proof of concept nearly impossible without costing something. Microsoft offeres something along the lines of 1gb of storage, 1 database, for 1 month. On the other hand, Amazon offers 20Gbs of a single instance (unlimited dbs) for 12, yes 12 months!.
That makes it a simple decision for me on which one to try.