Copied from Tcl Repository Wish List, and expressed in the words of Larry Virden:

• get a report on what extensions are in the repository but not installed
• get a report on what extensions from the repository are installed
• get a report on what extensions from the repository are newer than what I've installed
• be able to full text search the docs from the extensions in the repository
• be able to download source from the repository
• be able to download binary from the repository if available
• be able to support someone contributing binaries (recording info about options selected, who contributed it, staging area where binaries can be checked before releasing, etc.)
• be able to support someone contributing new source code (recording info about options available, depedendecies, who contributed it, licensing issues, staging area where source can be checked before releasing, etc.)
• private or public mirroring (perhaps with the CPAN redirection to nearest location for the user
• new and updated contributions notification (email, interactive, other)
• ability to express dependencies in a way that one could, if so desired, say build for me the source for BLT 2.6 and any missing dependencies and get back the proper versions that version of BLT requires that I am missing.