My two cents, which are sure to be ignored:
Instead of making up another ridiculous one-off villain a la Silva (ha ha, he's blond and a hacker like Julian Assange, aren't we clever), either go full-on fantasy and return to the Quantum plot, or (even better, in my view) make the next movie actually gritty and realistic, as in Bond having to single-handedly infiltrate some really gnarly part of the world, a Pyongyang or Mogadishu or Tehran. I'm no fan of Die Another Day, but at least it committed to its ludicrous fantasy, much like Casino Royale committed to covering some pretty minor (in blockbuster terms, at least) money-laundering and stock-rigging.
I'd also like to learn more about Bond as a character. Since Skyfall made such a big deal about his aging and not being as invincible as he used to be, fine, let's actually address the subject instead of coyly circling it: does he ever think about retiring, or what he'll do if he's made to? If he ever does, will he just hang around in tropical locales, fooling around with booze and women on a permanent basis? Will he still be chasing thirty-something tail with his cane and bad back?
The Brosnan-era Bonds made occasional references to the character's history as a British Navy officer; I assume the Craig Bond has some military background also. Does he have no friends or ties left from his Navy days? Does he ever want a family? Does he ever hang out with any other MI6 agents socially, or even at work (apart from briefings and the like)? Or is he just a soulless, "high functioning sociopath" with no interests whatsoever apart from whatever's bothering M and Britain at the moment?
Because frankly, I just didn't care whether Bond lived or died throughout Skyfall. Instead of accepting M's view of him as a disposable tool as an inherent part of the job, as he seemed prepared to do in Casino Royale, he acted all childishly petulant about it, later had his way with a long-time sex slave, and let Silva taunt him in the Underground tunnel instead of taking the clear shot.
So, yeah, it'd be nice to care about Bond again, and some solid character work could help nicely in that regard.