I would never buy anything directly through steam, but that's just me.
I really do not get steam?!?! If I owned Valve or who ever owns steam. I would buy Xfire & teamspeak, combined the 2 and add a tab for the stuff they want to sell or promote. Maybe even throw in a drive emulation utility.
If they want to go all out and create the ultimate gamer utility add riva tuner or some other utility to tweak your system (compatible with ATI & Nvidia).