Is there going to be an open Beta weekend before the release? And do they have a release month already ?

I haven't heard of a specific month, but Spring 2014 gives us an idea...

April 1st 2014 (Hey, it's even a Tuesday)

That would be the biggest troll ever. Release date of the first.... then BAM --- HAHAHAH it comes out on the 8th.

No to date/month aside from "Spring"

Yes (very very very likely) to open beta several weeks prior for stress testing.