Yu Suzuki is a troll without peer.

series that have huge sales are usually pioneers in their style of play....or radically changed (GTA3 became 3D) to get there.

So really there is no way to forecast this as it is gameplay decisions that makes the shift.
One thing is certain though... some people know how to do these games... Nintendo, Blizzard to name the most successful ones.

Music games were popular due to novelty gameplay.... it faded.
MW is a niche, there are many better shooters but this one is "the one to play"... it will eventually fade with no replacement.
GTA has also exhausted it's novelty...but more so due to competition/diversification in this style.
Gran Turismo was one such franchise in a well furnished area (so all the more impressive)... but they just didn't manage to hold on to their audience...

Next mega seller franchise will either be a new Nintendo franchise... or a new game from a developer that does not sell millions currently. We're definitely not going to see ME3, FableIV, Uncharted3, street fighter, Assasin's creed or any other copy/paste game start selling 15M anytime soon. Heck even Battlefield 3, a solid PC franchise, is going to struggle to get to 15M on 3 platforms.

I say Mass Effect 3 will sell ridiculously much.

Same with BF3.

CoD owns its growing sales to online multiplayer and GTA to its 3d enviroments and gameplay, as you said, so it was about technical progress that affected gameplay and appealed to a broader audience.

So asking what franchises will sell importantly better from now on, under this logic, is like asking which franchises will improve its appeal due to technical progress.

Well, if Nintendo can learn a lesson or two of what Sony has done with the Play, Create and Share series, I would say they might hold some winning cards.

Other than that I wouldn't know.

Battlefield... that's the most obvious choice to me imo

i would say Portal 3 too. Seeing how much hype and good word of mouth this game is having now and how Portal 2>>>>> Portal 1 in sales. Hopefully that's the case

And this is a far cry out but maybe kid icarus :P (it's just so awesome!)

uncharted i mean the game has been selling more and more and if naughty dog can stick to it ' it will be playstations halo

biochock - the first game was great but 2nd not so' but with the new direction it could deffiantly be a powerhouse

mass effect - pulled the old gears of war trick by announcing it and getting preorders then releasing it on a later date to build up the sales and since its multiplat it will deffiantly be a big hit

allan wake - the game is on the wrong system and i really hope it goes to playstation because those type of games arn't what xbox players usually play i was lucky enough to play the first and if it goes multiplat it could deffiantly be a much better seller

battlefield - we all know this 1 will do much better then 2 but lets hope they dont fall into the cod syndrome and make 1 amazing game then milk on that engine and formula for 4 years

Art Academy DS ... There is a massive number of people who would like to learn to draw throughout the world, but most software has been designed as a tool to create images not to teach people to draw. I could easily see this series hitting Wii Fit numbers if it was pushed hard.

agree for Saints Row!

Saints Row 3 is jaw drooping specially the last gameplay video
prey 2 looks insane too i was totally surprise with the gameplay

 
   Actually I agree with this one... the tutorials are simple, the tools are very well made and it has a very unique style...