Beta 1 lacks the Avalon graphics engine that is supposed to be the big change in Longhorn. This is actually very typical, as Beta 1 products of Windows releases rarley look anything like shipping products. I have a Beta 1 CD of Windows ME around here somewhere, and it was drasticially different then the Windows 98 Service Pack it really turned out to be.

OS X was also similar in earlier betas. None of the really advanced graphics stuff was in, so for the most part it had an odd OS 9 look to it, as they wern't sure what was going to be done yet, and just threw in the interface from the early OS X Server versions.