Speaking as a fan and GM, not a freelancer:
Actually, what I would like to see most are the following books:
MASTER OF SHADOWS – The Gamemaster Guide to SR
Maps, stats, goons, grunts, NPCs, how to run and all the other stuff in the GM section of the main rules expanded and explained in greater detail, stereotypical runs (and how to avoid them if one wants to), problem players, special rules ...
10 MATRICES – Virtual Places
A guide to 10 VR locations with visualisation, special rules (like: the ingame VR rules of that world, because you have to stay "virtually alive" to achieve whatever it is you are tasked to do there), adventure seeds etc. Think Second Life, WoW (or World Without Magic IV), Facebook VR and other sites transferred/elevated to a VR – and what dark stories there may be lurking. Should also contain a list of VR/AR services that are so important that they actually define Matrix culture (give us the facebooks, twitters and farmvilles of 2072+).
NEW SPRAWL SITES – if not included in GM book
and most of all:
DREKK – the Runner's Magazine
An ingame magazine (PDF?) like Street Samurai Catalogue or Rigger Black Book or the CP2020 Chromebooks and (most of all) Solo of Fortune: A magazine/blog/newsfeed that details a lot of topics that cater to runner's interests, features new equipment (with description and rumors and shadowtalk and ingame ads by the manufacturer) and lists of current music, sport events, a section on job offers ... new stuff can later appear in a new Arsenal, but reintroduce the story aspect of stuff, because STUFF IS COOL! Give us brands, give us some attitude, but not as a long rant of some shadowtalker or snippets of sociolist studies, but STRAIGHT IN THE FACE, as articles, posts, ads, spam ... a profile-generated magazine with content collected by an agent program of your everyday shadowrunner. With Shadowbabe (and Shadowhunk, if you must) of the month Smiley