HBO says: no Game of Thrones ratings for you! At least not today, so you can probably hold off on refreshing the site constantly (though we do appreciate the page views, thanks!) or leaving comments or e-mailing me pestering me for the numbers.
The short delay is presumably because HBO isn't interested in the results for just the 9pm telecast on the primary HBO being published before it can also at least tack on how many people watched any of the additional episodes.
Given the amount spent on the series (not to mention the marketing), it's hard to blame HBO for wanting to paint the premiere numbers in the best possible light. As a result, you have an extra day to make your own predictions.
Update: Vulture posted the preliminary metered market numbers that' I'd heard, but not seen, for Game of Thrones 9pm airing on HBO. A 1.6 household rating (about 1.9 million homes, not people, viewers will be higher since more than one person per household can watch). That's 43% lower than the 2.8 preliminary household rating for the premiere of Boardwalk Empire.