There are reports that Windows Longhorn has finally been given an official name, that name being "Vista". From ZDNet:
The advertising tagline for Vista is "Clear, Confident, Connected: Bringing clarity to your world," according to a video of the announcement posted by Microsoft.

Microsoft has also registered the domain name

The company is expected to announce Friday that the first beta, or test release, of Vista is slated for release as early as next week. The company is also planning to begin testing a server version of the operating system later this year.
A new name for an Operating System that many are getting bored of before its release. The opinion of many HEXITES seems to be that we need to see just what Longhorn... sorry Vista can do, not only what it looks like, especially given the UI isn't all that different from what we all use now.

Still, if a beta is on the way, we should get a chance to see what's on offer soon.