What would I like to see...
An expanded set of driving/riding rules - including a section on 'generate as you go' roads, similar to that in the old GW Judge Dredd Companion, but playable in the way that something like Dark Future was playable in its own right. Maybe this could emcompass flying vehicles, including skysurfing - so that chases and races could be played as a miniatures game or something.
A section on designing your own sector and blocks. Something like Citiblock only in more detail, and with advanced rules for destroying big stuff. I know all of this is covered already to an extent, but how cool wwould t be to play out a block war where anything goes really easily! (yes, rookies guide to block wars sets out mass combat and sructural hit points well enough, but still... big fights and chases should be fun!) - it shoul include guidelines on mapping a sector or part of a sector, and info on how to 'build a block' (i.e., number of levels, where the megaways enter and exit, locations of block parks, schools, armories etc)
Charts to generate details for random citizens. I lose count of the 'innocent civilians' that I have not detailed getting arrested by my players, so I have to make up thier details on the spot... also, a bunch of pre-generated background characters would be nice, just something to refer to when players want to talk to someone (or fight them!) who you only introduced for background colour.
Armour degredation rules, and rules for damage to equipment (beyond loss of hit points until it don't work no more - stuff like 'that bullet smashed your headlamps/damaged the respirator on your helmet'), and hit location rules beyond the called shot rules. I know that some people think this might slow the game down a little, so how about having these as optional advanced rules?
All in all, I would like to see more rules and less background - mainly because I am a regular reader of 2000ad and the Megazine and I already have all the background I need