I think you've got everything that I have on my "WinCE development" DVD apart from the SQL Server CE 2.0 install, which might be useful to some developers.
http://www.microsoft.com/sql/ce/downloads/ce20.asp
For people doing web development, PocketASP might be useful: I've tried this and it works pretty impressively on the HPC.
http://www.modezero.net/PocketASP/
Mail the authors for the HPC version: it does work, and well, too!
There are other dev tools, notably the GNU cross compiler, but until I've had more success with it I'd definitely not link to it from the page.