I know that Aron Racho and myself have taken a look at Cloud9, pretty sure he uses it in his From Zero to Cloud Service in 20 minutes using the Jive SDK and Heroku.
In short, for development in the cloud we are investigating this option and see a lot of alignment; however, we haven't fully vetted any one solution as being better than the others.
Definitely worth a try though, if you had to pick 1 to start with ... I'd suggest Cloud9, for no other reason than that is what we are leaning towards atm.
Hope that helps.
The Zero to Cloud blog uses Heroku, which I highly recommend. I have experimented with cloud9, and like it. Look to hear more from me about this in near future.