Feel free to email! That way you'll definitely get invited when we launch fully.
With regard to timeframes -- it really depends on what we discover during the beta. There are no major, obvious blockers right now, though.
Will launches in new countries start happening faster after the first one? I have no idea which part of the process is the major blocker for this kind of service, but I would imagine that if it's laws, then every extra country will take a lot of extra work.
I ask this as an Israeli that would love to have a good service, but seeing as we're a tiny country I doubt we're high up on the list :)
Stripe is a service I'd love to use, however I'm not yet at a stage(small revenues) where it would be worth bothering you to be part of the 'closed beta'.