According to Sky News, the turnout for London was 45%. I don't know where they have got that figure of course, but as Iain has noted on his live blog post, it is "good for the Tories because it means that turnout in inner London must have been much lower than in the outer Tory boroughs."
Have just been speaking to someone at the count at Excel and Iain's point may hold true. According to my source, the City and East GLA seat, which Labour is leading by about 65 to 35, is also the count that is farthest ahead.
The seat has apparently managed to count almost 50% of the vote so far, whilst the other seats being counted at Excel - that's the outer-boroughs - are only on the 38% mark. This would suggest that the turnout in the inner-borough of City and East is significantly lower than the others.
The real difficulty with the count though, and figuring out the actual figures is that there are only screens showing bar charts for the actual results. This means that you know who is "winning" but have to estimate by what margin. Given this the Lib Dems are getting confused and assuming that they're much closer than it looks because the graphs must be faked.
Speaking of the Lib Dems, here's some rather amusing news from the Greenwich and Lewisham count for the London List member. They're being beaten by the Greens.