The wiki is missing the query option of the count db command
http://www.mongodb.org/display/DOCS/List+of+Database+Commands

This doc seems more complete:
http://www.10gen.com/static/downloads/mongodb_qrc_commands.pdf

commandHelp("count") is also missing info:
db.commandHelp("count")
help for: count count objects in collection

I also couldn't find in the wiki info about specifying the database in a command syntax, not with a driver helper function (ns: <database>).

Other commands are probably also missing info so it'll be useful for others that implement drivers if you could update the docs.

Thanks