Some interesting news over at Techcrunch re: Phanfare moving 40 Terabytes of its backup data to Amazons S3 service and Amazon rumoured to be expanding their service to include MySQL support.
Amazon is going from strength with this proposition and rightly so. Its amazingly simple to use, its rock solid and its extremely cheap. For start ups out there it makes sense to use the infrastructure already available and not re-invent the wheel.
Their S3 service is also great as an online backup repository for consumers - especially if you use something like JungleDisk.
Adding MySQL support to their S3 and EC2 services would enable greater levels of functionality and should present some interesting applications.
Rightscale are also offering a beta trial of their new Amazon Web Services dashboard. Definitely worth a look.