My main suggestion was going to be:

SyncML

But asys3 already suggested it (though, under "Address Book", you put "dates" instead of "contacts" :-) ). And I'd add making sure that it not only works with funambol and evolution, but also GooSync (commercial, but ensures Google support).

My only other thing would be that under Todo list, it says "should optionally be finger-friendly" ... If that means "you can set a preference for 'drag scrolling with ultra-thin scroll bar and thumb size other widgets' vs 'stylus sized scroll bars and other widgets' vs 'all thumb sized, scroll bar and other widgets'", then yes. But if it means "finger-friendly is not a required goal of the project", then no. It should not be an optional goal, it should be a mandatory goal of all aspects of the project (not just Todo).