Firstly: Mike, it's so cool you can work on this and I'm very grateful that you are!
I am feeling very confident that My Moodle and the user profile page should be redeveloped in tandem for Moodle 2.0 as two sides of the same coin, probably as tabs of the "same" system (from a user interface point of view).
My Moodle = your personal "portal" page where you arrange your own Moodle front end (so you have a clear overview of what is happening and what needs doing for all your courses) as well as feeds and other info (eg a block to show your courses on an integrated Blackboard
server, for example!) It's also the place where you change your preferences and settings.
User Profile = your page for other people, may contain blocks with related information you want other people to see (eg recent twitter posts, etc). You should have some control here over what you want to allow people to see. Some of the existing tabs we have now in Moodle 1.x could become blocks on this page, and some of them could be moved to the My Moodle page.
This model is quite common on the internet these days, for example:
Facebook = Home + Profile
Twitter = Home + Profile
Flickr = Home + You