There's been talks of PostgreSQL in Amazon's EC & I know some of the EnterpriseDB people were looking at it. So maybe the people here would be interested in seeing how Amazon setup MySQL in the cloud.
A few things first:
1. I cannot find any documentation on IO metrics. The faqs specifically mentioned increasing CPU when queries seems slow, which doesn't make sense to me.
2. No out-of-the-box replication.
3. The automated backup is good enough, except for the "1 day retention period". Ugh.
I actually really hope this works out well for MySQL, because it means Amazon will have the infrastructure to support PostgreSQL as well.