Yahoo! acquires all the coolest companies. First it was Flickr, then del.icio.us, and now it's bagged Zimbra (for a reported US$350 million!), which I dare say is the company with the most Ajax know-how on the planet (with the possible exception of The Google).
If you haven't heard of it already, Zimbra is an open source email, address book, and calendaring server based on open source technologies tied together with a bunch of Java code. It competes with Microsoft Exchange, and is most noted for its rich web interface that makes heavy use of Ajax. We use Zimbra at SitePoint.
Zimbra was doing Ajax-powered email before Google made it cool. The company has also contributed a great deal of Ajax know-how to the world. Zimbra released of one of the first industrial-strength Ajax libraries, it helped to spearhead the OpenAjax Alliance, and has published numerous blog posts that have illuminated the sometimes murky waters of real-world Ajax development.
Now that Zimbra belongs to Yahoo!, I would only expect to see these trends continue. Yahoo! has made amazing contributions of both code and knowledge to the community lately, especially through the Yahoo! Developer Network. This open and sharing approach to web development seems to be something the two companies have in common.
As for how Zimbra the product (as opposed to Zimbra the company) is likely to change, that's something many people are a little more nervous about. Yahoo! has seemed—at least from my vantage—to favor PHP over Java for server-side development, and is reportedly looking to leverage its investment in Zimbra to make inroads into new markets. What changes to Zimbra might this strategy prompt?