Framework choice for a new app

Hello,

I'm going to start development of a new app and I'm wondering which way to go on the framework choice.

I was leaning towards merb but since merb and rails are merging I'm unsure.

What I'm mostly interested in is which of the frameworks is more future "safe", which will be easier to port/upgrade to rails3?

And which will be supported by the community in the future?

Best Regards

Since Merb is effectively merging into Rails and not the other way around I would suggest Rails. The reality is either way you will probably have to make significant modifications.