Yahoo has agreed to buy Zimbra, a startup that offers Web-based corporate e-mail (and a Next Net 25 company from 2006). The price is a hefty $350 million—one of the largest for a Web 2.0 startup to date. Yahoo is right to build up its portfolio of Web-based apps, but Zimbra is an enterprise app. Yahoo (YHOO) is a consumer company. So this could end up being a stretch for them (or its entry into a whole new market).
Update: A senior Yahoo executive just told me that the acquisition was more for Zimbra's technology than an attempt to create a wedge into the nascent enterprise Webtop market. That makes more sense. So expect to see some of Zimbra's gee-whiz Webtop features appear in Yahoo's consumer e-mail, contact, and calendering apps down the road.