Just throwing this out there....what's to stop Apple from completely dominating the console gaming market by simply getting people to buy a wireless Apple branded game controller and Apple TV / Airplay so you can stream the image to your HDTV? At that point you now have no reason that the current iPad couldn't play COD-MW3, or Battlefield 3, or Mass Effect 3. The processing power of the new iPad is equal to the 360 or PS3.
The idea has merit and is interesting but I don't think it will work (at least for the next couple of generations of consoles).The bolded is where your point falls off I think.
The PS3 came out in 2006. It has taken until 2012 for a tablet to catch up.
Once the Xbox720/PS4 come out, the equivalent same year tablets will be 5-10 years behind in gaming technology. You can't make up that level of technology,
especially in a tablet form factor, in just a couple of years, as you suggested. By the time the tablets catch up in technology to the PS4, the next version of the Xbox or PS will be available to again set it way behind.
Tablets will almost always be behind the consoles in technology for gaming. As long as gamers want the latest and greatest, tablets will be reserved for the Angry Birds type gamers, and consoles will be for the Skyrim type players.
The market for the Angry Birders type gamers is going to grow likely faster than the hard core gamers because of women IMO. It is an enormous demographic that the consoles can't crack but women buy the tablet/phone type games much more readily.