From a personal perspective, I would love if at least the Impulse client had a Linux version. Honestly the only reason I bought a new PC last year and a Windows 7 license was for 1 reason only: games. And my digital distribution platform of choice is Impulse by far. I use Steam, but really only if a title isn't available in Impulse. I think it's important to note that the reason i prefer Impulse is that it gives me much greater freedom over the games that I purchase. Easier access to files for mods, maps, etc. and I don't need to have the client running to play the games delivered by it.
Now that Steam is (apparently) releasing a Linux client I am totally stoked. I've been playing around with more Linux distros lately and I have to say that they have come a LONG way. As far as how "user friendly" they are I'd say Linux Mint for example is at least as easy to use as XP. The command line is used about equally for each. I'm Planning on buying a second HDD for that new machine i mentioned earlier for a dual boot system. And you can bet that I will get more games from Steam so as to install both Linux and Windows versions of games.
It's ironic really how the more 'closed' system, Steam, is the first one to migrate to the open and free OS world that Linux is, while the system that allows more freedom for its users, Impulse, seems to be content remaining on the closed Windows OS.