A Google Webmaster Help thread has confirmed reports that for new sites and some others, the reports in Google Webmaster Tools may be delayed.
JohnMu from Google said in the thread:
It looks like this is a general slow-down in our Webmaster Tools reporting pipeline for some new sites and not something due to your site in particular. I would just give it more time, though I'm afraid I don't have any particular timeline that I can promise. Thanks for your patience :)
There is clearly something clogging the pipes and Google for some sites. Whereas others are recently seeing huge increases in reporting numbers at Google Webmaster Tools.
Forum discussion at Google Webmaster Help.