Bad form to quote oneself, but I did call this yesterday.

Strictly's ratings were only 0.3m down on the first Saturday last year, so its not like its been crushed under the weight - in fact, you could say it held up pretty well (though I don't expect many will).
The difference now is the XF. First the Cheryl Cole thing, then more importantly, the Susan Boyle effect, have pushed these Cowell formats into the stratosphere ratings-wise. The media and this thread will continue to hype up the competition between SCD and XF, but I don't think theres any doubting the winner anymore, despite what Brucie might convince himself.
Both The Cube and Merlin did pretty well in their respective slots. I'm sure The Cube will be recommissioned now as its certainly one of the most successful gameshow formats introduced in the past couple of years. Merin did pretty well with a great share and the audience gain is encouraging. Could be pushed into pretty difficult territory as the slack of SCD's extra length is taken at the front of the schedule.
I guess the confirmed schedules for SCD Week 3 will prove whether the BBC have swapped SCD and Merlin for ratings, or because of SCD's length. If it was the former, then surely they'd swap the two and reduce the overlap by 45 minutes. But if its not and they simply refuse to air Merlin as late as 8.15/30pm, then they wont.