Late last month, Microsoft finally issued its first public build of Longhorn, build 5048. Also known cryptically as the Longhorn Developer Preview, Longhorn build 5048 was actually created on April 1, 2005 and does not reflect some of the advancements Microsoft has recently made. That was by design: Longhorn build 5048 is designed largely for device driver writers and, as such, does not include many of the user interface niceties we're expect from Longhorn. Furthermore, it actually represents a usability back-step from last year's build 4074. That's because some features, like the Sidebar and the new system-wide Contacts utility, are missing in action in 5048. There are reasons for these omissions. None of them are particularly good.