We’ve known this was coming for some time, but Youtube has finally announced a date for the end of its Internet Explorer 6 support: March 13, 2010. Starting on that date, IE6 users who visit Youtube will be presented with the above message to cajole them into upgrading to a modern browser.

Youtube won’t be killing access to IE6 users — they will still be able to view videos, add comments, etc. — it’s just fair warning that new features will not take IE6 into account. Users of other older browsers — anything below IE7, Chrome 4.0, Firefox 3.0, and Safari 3.0 — will also receive the same message.

Google also recently announced that it will kill old browser support on Google Docs and Sites on March 1, 2010, and it also plans to do the same for Gmail and Google Calendar by the end of the year. According to StatCounter, worldwide IE6 usage has been in steady decline for some time and is currently being used by 13 percent of web surfers.

Back in August, we reported on a group of startups that banded together to drop IE6 support by starting the IE6 No More campaign. Participating sites include Disqus, Justin.tv, and Reddit. There’s no doubt that many web users and developers would love to see IE6 go away completely — it’s slow, outdated, and leaves users wide open for malware infections — but that likely won’t happen as long as Microsoft continues defending the browser.