Microsoft & Yahoo! Search Partnership already happening?

I do not know if this is anything new, but today I was telling a friend about bing and that he should try it out because it is starting to drive traffic to our sites.

To our surprise, he tried some searches and we started seeing our own ads appearing in the results. Looking at the ads and links of the ads, we saw that they were from our Yahoo! CPC accounts.

Here is a screenshot today. It is not our ad in this case, but look at the URL in the status bar. It is pointing to Overture (Yahoo!).

Am I missing something, or has the Yahoo! / Microsoft partnership already started (perhaps in silent beta mode).

I am going to try Bing as my default search provider for a little while to see how well (or not) it works.