Don't know yet about when S6 will start airing, although I too have heard "sometime in May", or even if it will be the last season, but I finally have a date for CN's Upfront presentation- April 3, to be held in Manhattan. In previous years, it's been held in February, so understandably many are thrown off by it. The later date is much thanks to (you guessed it) the WGA strike. But, come April 3, I'm sure we'll get answers to at least one of these questions.
I agree with PBL here in that Foster's is doing very well, is bringing in most of the ratings for CN (along with
Chowder right now), and is even getting more licensed merchandise on shelves, so it's probably safe to expect a season 7 to be ordered. But we'll still have to wait and see for sure.
