According to a report via Uncle Dave, there's talk that Fox may want to have SmackDown air for 3 hours when it makes its debut on Friday, October 4th this year. The idea, according to the report, is that they might air the first two hours from 8 to 10 on Fox and air the final hour on FS1. This is said to be something that Fox executives are talking about and isn't Vince's idea and that while it's by no means a done deal, such an arrangement could net WWE upwards of an additional $50 million per year so that's a definite incentive.
This sounds like a groan worthy situation but I think that depends a lot on the format of SmackDown. We've all read reports alleging that Fox wants SmackDown to be a much more serious, more sports like program and, if true, then that is something to consider. I think everyone is curious to see how such a format change would affect WWE and it might not be a bad thing if the additional time is filled with competitive matches and meaningful segments rather than pointless filler of the "sports entertainment" variety. WWE has hardly ever utilized the additional time of Raw wisely, in my opinion, but this could be a completely different situation as every report I've read says that Fox is going to be much more hands on than NBC Universal has been with WWE programming.
So yeah, take it for what it's worth but if Fox wants this to happen, it'll happen.