I recently made a somewhat related comment in an old thread regarding start dates here:
http://forums.omnigroup.com/showthread.php?t=21734
I think in general it would be really good to have similar options for start dates as there are for due dates today - badges, notifications, the forecast view etc.
There seems to be at least two schools of thought - those relying heavily on start dates (me for example) and those who instead use due dates heavily. Today, the use of due dates is much easier because of the additional options and features available. However, to me, using start dates works much better but I do miss the additional features very much.