While speculation continues about whether Microsoft will acquire the company, Xobni is pressing on with its development work.

According to Erik Schonfeld over at TechCrunch, Yahoo has a working prototype (not yet in beta) built in to Internet Explorer that integrates email from Yahoo Mail and Outlook into the Xobni sidebar for both applications. Reportedly, emails from Yahoo Mail are visible and searchable as conversations in the Outlook plugin and vice-versa.

No word on when the Yahoo Mail work may actually be available to Xobni users, but it’s nice to hear evidence of Xobni’s oft-repeated claim to be working on platforms other than Outlook. I just wish that Xobni for PINE was more than an April Fool’s Joke …