It may not be the exciting new kid on the block, but Microsoft’s Internet Explorer is still the dominant browser in the U.S. And the company has surely bolstered its market share a bit with the introduction of IE9. That latest version of the browser did some rather brisk numbers in its first 24 hours yesterday, hitting 2.35 million downloads in that time period. That number breaks down to around 27 downloads a second. As of January, IE is still on top, with 56 of the total U.S. browser market (down a percentage point from December), Firefox was in second with around 22, and Google’s Chrome had managed to make a dent in the market with 10 percent. Any gains made by Microsoft with the latest edition will likely be affected by the upcoming introduction of Firefox 4, which is due to hit on March 22nd.