> The only reason to migrate away from GAE would be if you find out that your application doesn't work well on it (pricing, scalability, etc) or if Google decides to kill GAE entirely. Hopefully you do the analysis of your application before you decide to use GAE (ie: you can't blame GAE for you deciding to use it)
This seem too simplistic. Off the top of my head, you may leave because:
* you want to do something new in your app that is not possible/effective to do within GAE
* you find another option that is cheaper
* you find that some of the assumptions and architectural decisions you took on day 0 no longer hold
* you did the initial analysis, and it was wrong
I do agree with GAE being awesome and lock-in not being so bad, but I doubt the "you have it all figured out before building it so it's going to work forever" idea.
FWIW, I frequently want to do things that are not possible/effective on GAE. And so I do it - several of my GAE apps communicate with services I set up in rackspace cloud (30-40 ms of latency away). It would probably be even lower running in Google's cloud service, but I haven't gotten an invite yet.
GAE is not "all or nothing". You can still run exotic services in other hosts. Or, for that matter, use GAE for specific services in your "other cloud" app. You get two bills. Not much of a downside.
This seem too simplistic. Off the top of my head, you may leave because:
* you want to do something new in your app that is not possible/effective to do within GAE * you find another option that is cheaper * you find that some of the assumptions and architectural decisions you took on day 0 no longer hold * you did the initial analysis, and it was wrong
I do agree with GAE being awesome and lock-in not being so bad, but I doubt the "you have it all figured out before building it so it's going to work forever" idea.