Other way I see it working out is Uber gets so optimized that they can have a driver double dip with a delivery and passengers going on the same route.
What will passengers think about having their ride delayed? Lump it into Pool and partially rebate them?
What will keep restaurants from #&@$ing around with their notifications (e.g. ready) for a partner who they don't really like working with?
(Personally, I switched to Lyft and don't use Uber products anymore)