Saying tablets will replace consoles is the same as saying laptops will replace desktops. While laptops may become replaced (mostly) by netbooks, as they fill the same mobile market, desktops and laptops are entirely different markets. Same is the case for consoles and mobile devices. We don't want a mobile device to replace a console, because a fixed device will be more powerful at the same price, and thus be a better option (not to mention the obvious deficiencies in touch format controls). Tablets may replace the mobile market, but unless they condense to only a few competing companies (so theres less differences to worry about), and they include methods of input usable for games (i.e. a d-pad, analog stick, buttons, making them not tablets anymore), they won't even replace the mobile market because of simply being inferior to systems designed with games in mind. Once we hit a technology (or heat) ceiling, this may change, but that's a long way off.
Companies don't seem to realize that the market for things like the wii, kinect, move, flash games, and games for tablets has nothing to do with the market for ps3, 360, and (traditional) pc games. Microsoft is not gaining converts from normal games to kinect, and no one is dropping a psp for a tablet. These products are gaining customers who aren't interested in "video games". They are two entirely different categories, that in many cases don't overlap at all. Most people that would play crysis are not even remotely interested in bejeweled, and vice versa.
There's a larger market for casual games, but casual games are a completely different product than normal games. Just because they're both vehicles does not mean Ferarri should start producing dump trucks while CAT starts producing supercars. Videogames and casual games are the same way, and companies should realize that.