What's next
ITV2 snaps at Sky One's heels
Basically there are several processes at work here: firstly ITV2 has been doing well due to the endless cross promotions on ITV1 as well as cross-channel tie-ins, whilst programme promotions on Sky One are relatively rare on non-Sky channels. And since BSkyB has no free-to-air equivalent of ITV1 - yet - it can't do the same for Sky One as ITV has been doing to ITV2 and ITV3.
And despite Dawn Airey being in charge of programming, Sky One still has to gain credibility in terms of its own programming, and the pause in the Star Trek franchise combined with the decline of The Simpsons couldn't have come at a more critical time for the channel. Other programmes such as Hex and 24 have only been moderately successful and Deadwood has been a dead disappointment.
It's therefore very likely that BSkyB will soon want a free-to-air entertainment channel even just as a promotional aid. Since acquiring ITV would turn it into a blatant commercial television monopoly, Channel Five is the only viable option (if RTL will sell) apart from converting Sky Travel on Freeview into some form of cut-down Sky One, but either option might be seen as a 'defeat' for the concept of pay-TV.
Expect an announcement from BSkyB relating to something on Freeview in the not too distant future, but Sky of course is still capable of surprising us.