To deploy or not to deploy on App Engine

I am nearing the end on a project i have been working on and am trying
to figure out where to host it. I am very tempted to host it on
google's app engine. you get a ton of space, band width, and processor
all for free!

I was hoping to get some advice as to what people think about deplying
on the app engine.
Would it better to wait until ruby is supported? Are there perfomrance
issues with using JRuby? What would happen if ruby were supported in
the future, would transfering be a pain?

Do you use active record on your project? If so, google app engine is
not for you.

Take a look at this post, it explains some of the limitations:

Leonardo Borges