Apple announced a rebranding of their .Mac service earlier this morning. It’s now called MobileMe and features online versions of Mail, iCal, and Address Book, so you can access your email, calendars, and contacts (watch a demo) from any PC.

Any PC not running IE 6, that is. From the email sent out to .Mac subscribers just a few minutes ago:

To use the new web applications, make sure you have one of these browsers: Safari 3, Internet Explorer 7, or Firefox 2 or later.

There’s still a significant number of PCs out there running IE 6, usually corporate machines that need to access intranets or other web apps that only work with that browser. A quick look at the stats for Basecamp’s marketing site shows that 31% of all IE users are using version 6.

So it’s interesting that MobileMe is the first major web application (that I know of, at least) that’s dropped IE 6 support completely. It’s a gutsy move, since Apple’s billing it as a way to access your data from anywhere.

And I’m hoping it’s the beginning of a trend. IE 6 is definitely the most painful browser for us to support – it’s seven years old and doesn’t even fully support the CSS 1.0 standard created in 1996. Microsoft’s done an incredibly poor job of getting users to upgrade. It looks like it’s going to take pressure from big apps like MobileMe to seal the deal.