Some (most) stuff has already been said, I think, but here's my "wishlist":
• taking an engineer allows you to take a mortar/cannon battery (0-2 cannon/mortar per choice) as a single special choice.
• add a rule to show the volatile nature of gunpowder (i.e. when destroying a cannon, all units within d6 inch get hit by explosion) or engineer/... making last-ditch defence (selfdestruction of gunpowder-stock).
• generate steampoints of stank at start of battle and give players choice when to use steampoints and how many (i.e. 3 in own turn, 2 in opponents) - overpowering?
• add a master engineer (lord choice)
• remove spearmen from list. Instead use halberds as spears (2nd rank) and halberd (first rank).
• Greatswords can have magic banner (standard)
• Add cult-related stuff (i.e. Banner of Sigmar: unit becomes frenzied)
• More huntsmen-units possible and/or increased BS and/or Longbows/xbows/hgun options
• modular options for the stank (no cannon, but mortar i.e.)
• modular options for knights (like a vow? - saw this mentioned in a white dwarf somewhere)
• modular options for pistoliers (lancers?) and/or make them a core choice in certain armies
• add some real special/rare stuff: i.e. kind of skirmishing unit of fanatics, zealous witchhunters (fearless?), college of magic-adepts (boost spells of wizard of same college?), blunderbuss-armed units
In general, I think we have too many basic stuff and nothing really "freaky" that represents the Imperial background...
any thoughts?