They aren't just now starting to build the software, why would it take two months to reveal it to the public? They have already shown us multiple aspects of the software, how it works and what not. There is already a script that tells you if you're ready to upgrade, which gives the impression that they are done creating content and already know what minimum requirements and whatnot for the software will be.
This latest update wasn't saying they were preparing for release, but rather that forum hosts should start preparing for the beta that will be coming shortly.
There will only be a week or so span between the public reveal and the start of beta testing. IPB has a very large and strong community of intelligent and fast-working members that will be finding every little bug and fix required in a short time-frame. I
highly doubt this is going to take six months.
Also, ATRL's tech team has been preparing for this for a long time and they are about ready to start their beta testing almost immediately after they get a hold o the software. I'm not sure where they stand as a client on IP right now, but if they are lucky enough to get into the beta than they should be able to kill two birds with one stone and shorten the time before ATRL's upgrade sees the light of day.
It's still fully possible that the ATRL upgrade will arrive by the end of this year as a Christmas gift.