I have and I have to say it's an excellent platform, it has a good feature set, competitive pricing (matches EC2) and they're doing tonnes of work to it and throwing a lot of cash at it. It's not tied to the .Net framework(you can run php, Java, RoR etc etc on it).
Interestingly they also announced Windows Azure appliance yesterday at WPC10 which is the first proper effort to solve to private cloud problem and having spoken to businesses looking at our product this is definitely an issue for B2B SaaS applications.
I just don't understand the immediate disregard for anything Microsoft does, yes IE has been sh*t however it's foolish to write off every new MSFT offering as the "next IE" without understanding what it is offering.