[Brando]

For a blog? Good idea. E-commerce? Good too. Pretty much anything that is static and not updating frequently.

You may want to reach out to a rep at Rackspace or Amazon and get an quote. Be sure to highlight that you have a community site (forums) with thousands of active users.

I would vote to keep the forums dedicated but look at implementing a CDN (content delivery/distribution network) to speed users' load times. The e-commerce side of your site could easily be moved to the cloud.

Of course, it wouldn't hurt to get a few quotes from various providers or IT professionals.