I'm addicted to some of my favorite series. If a new Zelda came out on a cloud-based system, I'd still buy that system.
When a new system (non-handheld) comes out, we wait until there's at least one game for each of us before we buy it. We had an XBox 360 really early, as I wanted Kameo (love Rare games) and Ninety-Nine Nights, and he wanted something like Perfect Dark or Quake 4 or something.
We didn't get a PS3 for a long time. There were a few games he wanted, but nothing I'd get. I finally caved when Metal Gear Solid 4 came out, since he loves those games, and Little Big Planet had been announced by that time, which I thought looked fun. (Aside: LBP gets WAY more play in our house, since it's something we can play together.)
Handhelds are generally at launch, because I don't go anywhere without my DS (now 3DS). I DO regret getting the Vita as early as we did, because I've played maybe an hour or two on it and all he uses it for is soccer.
Point is, if good games and unique experiences come out for these cloud systems, I'll still be getting them. I won't lie. But I'll just keep collecting for my DS, and only buying games I really want to invest time in on those systems. I just think they're being very narrow-minded about this. As of April 2010, only 73% of Xbox 360s had gotten online. Are they going to cut out 1/4 of their sales just to eliminate the used games market?