The subject was covered in some depth recently -
http://www.railforums.co.uk/showthread.php?t=101925
To summarise from memory:
1 - There is a lot of work planned, both definitely for the nearish future, and aspirationally for the more distant future.
2 - Several of the retail units are going - Burger King have been served notice already - in order to open the space up a bit.
3 - No one other than thee and me, yorksrob, seems to care about all the already-extant perfectly adequate exists from the station which NR choose not to use.
4 - The barriers are a crush partly because they are broken. I go through them frequently and see large numbers of people whose tickets can't be read. There also seem to be barriers locked out of use having failed at all times. The industry seem able to install working barriers at London terminals; it is a mystery to me why NR Leeds cannot.