S3: $0.140 per GB (at the most expensive rate) vs. Google: $0.17 per GB (at their only listed rate)
The rest seems to be the same though.
The whole 'we've decided to kill that product, you've got 30 days to get your stuff back' and the 'we lost a switch or something and we'll be back online day after tomorrow' kinds of things are still concerns of course.
I've always been impressed at the prices Amazon could charge for S3 and keep it a going concern. I'd love to see the breakout on that revenue but I'm sure that isn't going to happen any time soon.
[1] http://www.newegg.com/Product/ProductList.aspx?Submit=ENE...
Also, don't forget bandwidth charges if e.g. some of your s3 access does not come from ec2.
You could add into the cost / GB of bandwidth to access the files, not as easy to factor into a TCO model in the personal use case.