Jennifer Slegg at JenSense reports today that Microsoft has disclosed the long awaited name of their new contextual ad program, ContentAds, as well as a much narrower timeline for the program to launch. She found this information on the upcoming Mix06 conference web site within the session information.

Session information is as follows:

Introducing adCenter – Microsoft’s Next Generation Advertising Platform
adCenter is the next generation of online advertising that will allow you to conveniently plan, execute, and adjust your online advertising programs. Get the insider view of our current search advertising pilot in the U.S., our plans for ContentAds in 2006 and a preview of the innovations we're testing at the Microsoft adLabs.

So Microsoft joins the fray with the others, first as a search engine, then in the arena of PPC advertising and now the contextual advertising market. This will give publishers an additional source of contextual advertising to test on their sites, Google and Yahoo being the dominant ones right now.

I'm not sure how many publishers however will flock to drop either AdSense or Yahoo Publisher Network (YPN) in favor of this new program from MSN. With both Google and Yahoo, you can run or the other but not both within the same web pages. I'm sure ContentAds will have similar terms of service with. In the meantime, Google still leads the way with AdSense as being the most effective overall which was touched on by Jennifer in another report.