Yes Steve, I've been using it for about a year. I've been very happy with it, although I now generally embed most of my videos from YouTube instead since I earn more advertising revenue from them as a YouTube partner.
Beware that bandwidth is expensive through amazon. We have a lot of database servers in the cloud that handle cpu intensive queries nicely without bogging down our own server. However, when we recently needed to transfer a 300GB image back into the office we found it was cheaper to buy a hard drive, ship it overnight to amazon, pay their techs to copy the image for us, and ship the drive back, than to pay for the data transfer rates.