i personally (no inside info, just gut feeling) am sure that we will at least have at least a closed beta before end of summer.
I highly doubt this.
With all the announced changes there will be lots of testing going on at sirius. It will take a lot of time. Then, at the end of july, the thai server will resume service and they'll have to use some manpower on hotfixes and stuff.... this will take time too.
Then, as we know how aeria dealed with this before, we will propably have a 3rd alpha to test all the new stuff ...and that's a lot to test...all those advanced battle and trade classes, the new systems, new dungeons and so on...I guess there will be at least a one month alpha.
I think there might be a CBT early 2013 and then a OBT somewhere middle 2013 with the final game starting soon after OBT has passed.