There is some discussion going on based on
an article at
Bink.nu showing Microsofts new releases in 2005. The list in this article contains Sharepoint 2005. The releases are based on as well facts as assumptions, which is in this case probably an assumption that is not valid?
The next version of Sharepoint should be exciting. It would cover the release of VS.Net 2005 and ASP.Net 2.0 which opens doors on webpart and web development. However, Sharepoint is part of the Office System and would therefore be more logical to be released with Office 12 in 2006.
I'll place my bet on a beta version :)