If where you write, "Main menu options will be ordered by usage frequency" you mean dynamic reorganization, I am concerned.  I have found Microsoft's and Adobe's efforts to "streamline" their menus by hiding things that haven't been used recently and moving items to the top just after I get used to finding them elsewhere around to slow me down more often than it helps.

Adding a short "frequent tasks" list \\ sort of like recently used files in Office would be useful, but I would suggest that it should be distinct from the main navigation structure. There is a real risk that dynamic reorganization will actually hinder users by frustrating them when features they're still learning move around.

(Unimportant: Is there a special meaning for "wizzard" with two "z"s instead of the usual one? I tried Googling and found a couple references to musicians...)