From the current perspective it doesn't look like ypool will be back anytime soon. We are experiencing some technical difficulties that will likely force us to switch to a different machine, maybe even a different provider. If thats the case it will take at least a day until everything is up and running again. The good news is that no data was lost.
I recommend switching to a different pool for the meantime. I'll keep you updated as we go. I might also setup a IRC channel later.
Follow our twitter for updates:
https://twitter.com/ypool_net