It's a completely different market segment. It will get larger, you'll probably see some eventual publisher consolidation (it's already happening now), and entry of barrier into the market place will get to a point that only publishers with real backing will be able to succeed in it. (in that the store will just a distribution point, not a place to do the marketing) However, a replacement for console gaming it is not.
the primary reason? The mode of consumption is completely different. For most of us, the act of gaming is us sitting down in front of a TV/PC and saying to ourselves, "I'm playing this, I'm going to dedicate some time to THIS activity". you have to remain fully engaged for that time period. The way you consume a mobile game is "I have 15 minutes at the bus stop / on the toilet, and I don't want to be bored". The design priorities for the two segments are apples and oranges.
Now, there is ONE segment that I can imagine some cross pollination and that's the emerging gamer crowd, aka kids. Right now, I see a lot of kids (say, below the age of 10) who play both mobile games and console games, but focus heavily on mobile simply because that's what they get more time to. (any time they're out to dinner, on a long car ride, etc) In those instances, they're looking for easy entertainment rather than say, a full engaging experience. However, for a lot of kids, there is very little difference. Playing a console type game with a bunch of mechanics attached to it is work. To be fully immersed in a game experience takes work and a fundamental amount of knowledge. And for a lot of kids, that's not what they're looking for. it's not like for a lot of us where back in the day, you either played the ridiculously hard Megaman 2 or it's nothing. Now, there are a LOT of alternatives.
The sweet spot is when they move past that tween years and want more out of their entertainment. At this point, the determination of their type becomes clearer.
But unless the desire for a full experience goes away, I just can't imagine the console / PC market going away.