I think it is safe to say that there will be another Geo. Jack has intimated as much. However, an actual release date has not been given. He has also said that he want's to get out of the yearly releases at some point, so read in to that what you will. The popular rumour is that "something" will be released in February, or maybe March, to be unveiled at one of the various industry events that occurs in that time frame. However, Planet themselves have not confirmed or denied this to the best of my knowledge.
As is always the case when people start talking about the next Ego, Etek or SL, yes, there are time frames when new products tend to get released, but when it comes right down to it, Planet will release things when they are good and ready, and it'll happen when it happens.