Yes.
No.
Define "managed solutions"... Like a do-it-yourself package for hosting on EC2? Not aware of any, though there's plenty of tools for managing cloud resources out there.

Managed solutions, meaning some kind of hosting company that uses the Amazon architecture, does all the techie stuff etc. We pay for the service + amazon fees.

I have been working with EC2 since the early beta stage of development, it might be a very interesting solution, however it is still not a viable "standalone" solution, "managed or otherwise" The cloud as a whole is very interesting in the many different ways you can use it to create highly scalable solutions. However for the average user, it is just not user friendly, Amazon has a problem with documentation for the average user.

Some of the support options read like a NASA white paper.

I use Amazon for a number of cloud data solutions, but everything runs in parallel, I would love to see a stable, simple service standard come out of all the different AWS technologies, however right now, at this time I would have to just say no.

I don't know what the pricing is, but Cloud Computing Management Platform by RightScale does this (looks expensive).

In general, just the most basic EC2 cloud server without management is going to cost at least $75 per month.

There are other options for managed cloud hosting.. Media Temple, Rackspace, etc that you may want to look at.

What exactly are you looking to do that makes you think you need cloud hosting?

Just recently, what seems "impossible" happened to EC2: It suffered a major down time and several high profile sites like Foursquare and Reddit got affected, and a few suffered unrecoverable data loss. Lesson is, even if you're on EC2, you should still have your own contingency plan.