Currently the draft is about 90,000 words. If it were published at that length, it would be the shortest book in the series. However, I am confident that the second draft will add 10-20K words in length. Lots of stuff to add in that I noted during the writing of the first draft. That will make it about the same length of Psion Gamma.
Why is it so short? Well, because that's the way it was. I know some readers want the longest book possible, but I can't add on length for the sake of adding on length.
So what am I doing now? Going back to finish Tale 3. After I make significant progress (hopefully finishing it), I'll start rewriting Omega. I don't want to put Omega off too long, but I also need to take a break from it. My most ambitious timetable for publishing Omega puts me at Late Summer. If delays happen, we're probably looking at late 2015, like Nov or Dec. As always, I'll keep you posted.