Ryan Gavin on Windows blog posted that with Internet Explorer 9, Firefox 4.0, and Chrome 10 all hitting their final releases recently, drawing instant comparisons around downloads or initial usage isn't possible. Why he says:
"Every browser has a mechanism for updating their users from a previous version of a browser to the latest and greatest. For IE9, it's done through Windows Update. In the case of FireFox 4.0 and Chrome 10 their update mechanisms are turned on as part of their initial release to web (RTW). In the case of IE9 which RTW-ed on March 14th, we just turned on WU for IE9 RTW yesterday -- even then only for existing IE9 Beta and RC users. We've yet to turn on any updating for any Windows customers who've not previously downloaded IE9 Beta or IE9 RC. So, every IE9 download is from a customer actively seeking out IE9 and downloading it. No automatic update or in-product prompts. As a matter of fact, of the downloads we've seen through Sunday, March 27th, over 90% have come from non-IE9 RC and Beta users. And remember, we report completed downloads -- not attempted downloads where a user may hit a download button repeatedly but without fully downloading IE9."
"IE9 willn't be broadly rolled out on WU until the end of June. We do this because we've hundreds of millions of business customers that rely on IE and require an appropriate window of time to plan and test their deployments. We also have a responsibility, as the most popular browser on the planet, to ensure that IE9 is introduced in a timeline that allows web site developers to have the chance to ensure their site is 100% ready.
The net of all this's that any comparison of browser share adoption at this point is premature at best, and misleading at worst. In a few months we'll be better placed to look at the share of the latest browser versions and get a sense for relative progress and adoption."