7.8 million watched Question Time - an X Factor moment for the BNP?

It's been a while since an overnight figure stopped me in my tracks, as this number for last nights Question Time did this morning. Which is a bit odd, since every Monday I seem to get another email from ITV heralding the record figures for X Factor -here's this week's introduction
"Last night’s The X Factor results show on ITV1 attracted a record peak audience of 14.8 million viewers, 50 percent audience share, the highest ever volume for the programme – eclipsing the 14.6 million peak audience that watched last year’s final."
The trouble with this is that, well, you sort of know it's coming, what with Cheryl Cole's appearance being hyped all week, plus Whitney's return and so on. 14.6 million - yeah, tremendous figures, keep up the good work.
But almost 8 million for an episode of Question Time? The show turns in around 2.5 million most of the time - it had a blip in the spring when it caught the banking crisis mood, and almost hit 4 million. But I don't think its ever achieved anything like this before.
Maybe the parallel with X Factor isn't so odd. The programme had massive pre-publicity through the news and discussion about the BNP appearance and viewers presumably tuned in to make their own judgements, just as they do each week with the X Factor contestants. In one respect there is no similarity - you can't vote on the night for an individual panellist, so viewers will have to wait for the general election. Only then will we know whether the programme exposed the BNP to scrutiny, and whether the resulting publicity turns out to be oxygen or poison.