We include our real email address from a real person for just that reason. Only problem is we get a LOT of out of the office messages etc. We have gotten better at filtering them out though.
Heroku and Engine Yard (for their cloud service) are just front ends to AWS anyway. Your basically paying them for the luxury of not having to deal with AWS. So as long as they don't get undercut by a competitor and all their customers flee, they should be around for a while. That or their owners get greedy, sell the companies, and the new owners move to "more economical hosting". Na, that never happens. ;-)