Great interview! I hadn't heard of Alex before now, but he looks like someone to watch.
As for PC gaming, is it really any wonder it has declined in relation to consoles? How can the PC game industry compete with consoles when PCs cost 2000 dollars to play a newly released game well, when consoles cost 1/4th of that? It's surprising to me the PC games industry has done as well as it has. The barrier to entry is HUGE for PCs. It has nothing to do with being online.
Its also is the whole reason "casual" games are considered casual is because they are budget titles. It's not their download size that matters so much, it's that they require very little in the way of graphics hardware, and can be played on almost any computer. The games themselves are cheap. Valve's Steam has shown that even AAA, huge games are easily distributed online.
I would think that the really important part of online games is not "instant gratification". I bought a game a few weeks ago on Steam on a whim. It was easy, because I don't have to go buy the game or install it. All I have to do is click a few buttons and in a few hours it will have downloaded and I will be able to play it.
I think the biggest advantage to online distribution is not instantly getting what you bought, but the ease in buying it. People are going to be willing to wait a few hours, or even a few days, to play a big budget game if they can afford it. They'll download the "casual" games if they're computer is crap and/or they are strapped for cash. No one says, hmm I could buy Civilization IV, or I could buy Pacman. Well I can download Pacman in 2 seconds so I'll get that!
And that's really the difference here: budget. Even in the future when we can dowload at 25 gigs a second, if it still takes 10-20 million to make a "next gen" game, there is going to be a market for the games that cost 10,000 dollars to make.