korell: Maybe these oddities really are just down to Steam silliness and lack of updated descriptions (such as examples of games where third party DRM is removed yet the game page still has it shown).
If the CoD games on Steam do indeed have no 3rd party DRM and do download the fully installed game files as expected then yes I may purchase them over time at some point. However, at the prices they are currently at, not a chance (and I've plenty to keep me busy in the meantime).
satoru: Games with 3rd party DRM tools usually state so in the description
http://store.steampowered.com/app/48220/?snr=1_4_4__104_1 Look along the right hand side. Under the metascore you'll see the normal boring stuff like Title/Genre/etc at the bottom
3rd-party:DRM
Or Darkspopre
http://store.steampowered.com/app/99890/
At the very bottom it talks about how you need a persistent connection to ea.com
Yeah, I know about that, but it isn't kept up to date and sometimes doesn't state when it is present.
Take S.T.A.L.K.E.R. Clear Sky. It lists the third party DRM as TAGES. However, it was removed (only some inert files left in the installation folder now) but the page wasn't updated.
Whilst Bioshock still states "Game requires Internet connection for activation" but the SecuROM activations were removed from the game.
GTA IV states SecuROM with unlimited activations, but I thought it was a GFWL game?
Borderlands: Game of the Year Edition lists no 3rd party DRM on the Steam page, but two of the included DLCs are SecuROM 5 activation limit. However, the Borderlands DLC pack does state that some of the contents have SecuROM 5 limit activations.