1)Make the joblog/history log searchable while interactive instead of a tedious process of scanning through a spool file.
2)Push the iSeries brand out further. Compare capabilities of iSeries vs. SUN, WINTEL etc.
3)Change the standard green screen to a more dynamic one so messaging is set in a priority mode(Red-urgent, serious.Yellow-Lesser on both. Green-Normal, informational.This is not something that new-Mainframe uses such interface.)
4)Start adding capabilities that 3rd parties vendors normally supply.Microsoft has done this and it raised the bar on what the vendors now offer. Perhaps there are tools not even offered by 3rd party vendors but may be free/shareware that works very well and has for years. Incorporate it.
5)Be dynamic and evolve. Yes be true to your origins but look at the market place see whats out there and a)emulate what works or b)innovate whats needed.