@nucl34r14: believe it or not, I kinda "accidentally" had the co-op campaigns. They are very untidy and they cause internal errors a lot. I removed that game mode from version 1.5...
Version 1.5's game modes are split in two. The first, called "cross-tech" modes, are basically version 1.0's general premise - you can eventually, after teching up a lot, get access to different country's things and even other faction's things. Then there are "normal" modes which are basically non-cross-tech - they don't have the option of getting other country's things etc.
For both modes, the 5 "super-secret" things are accesable by constructing a mega-expensive, disableable "Reinforcements Beacon". But in cross-tech modes it's easier to get the secret stuff, since building things from all 3 factions (e.g. all 3 barracks) also gets you access to some secret stuff. In non-cross-tech modes, it is still possible to get secret stuff without a Reinforcements Beacon, but it's much harder as you'll ahve to capture many things from your enemies, e.g. you will have to have all 3 Armageddon Engines, etc. etc. and some things aren't even capturable.
In short, you can play WRV1.5 as a spammy n00b, as an uber-1337 haxor, or anywhere in between, so hopefully there's something for everyone in it
By the way, I believe I made a post about the game modes with a screenshot. In the "Mod Progress" topic it was, I believe. Can't remember exactly - search for it yourself