They generally don't tell anyone in advance of the release date, as far as I know, but the tickets certainly became available much earlier last year.
For example I usually buy my tickets to Crete for April as soon as I can when eJ publish them.
- Apr 2009 flight I bought on 8th Dec 2008 ( I believe the email came in on 5th for Gatwick)
- Apr 2010 were purchased on 16th Aug 2009 (I think they released those Gatwick on 14th)
So they were nearly 4 months earlier last year. Don't forget that they also IIRC let the regional tickets out slightly before the Gatwick ones.
Hope that helps
Pete