Why does every game have to be either AAA+ or indie, with nothing in-between?
Here's an idea. Remake the original Deus Ex using something like the Source engine, with HL2-level graphics. That engine can handle both crpgs and wide open areas much better than most people think - e.g. Vampire the Masquerade:Bloodlines. That would make it less ugly, so newer players could get into it, while preserving the original gameplay.
Some indie developers do that all the time - e.g. Vogel keeps re-releasing his Exile/Avernum games as he updates his engines so that newer customers have the same gameplay but with better engines and graphics.
Or how about this for another idea. There is still a huge market of gamers wanting complexity and challenge in this genre of game. We see that in the way that games like VtM:B are 'long-sellers', continuing to sell decent units a good decade after the game was released - FO:NV looks like it will have a similar following, in that while its initial sales were lower than FO, it's continued sales are much much higher, and it is still selling really strongly.
Even the infinity engine games (Baldurs Gate 1 and 2, Planescape: Torment, Icewind Dale series) still sell units.
The problem isn't that there's a lack of market (though quite a few of that market will need to be enticed back into gaming, having abandoned the hobby as the industry made clear that they no longer wanted their business), it's that it's easier to pump out games that can be made in one year, and aim them at the biggest market possible, meaning that genres (like the Thief/System-Shock/Deus-Ex style of games) can have a profitable market and still not get made.
But many of the fans of that genre don't need or care about cutting edge graphics, and flat-out hate cinematics and cutscenes. SO....why not do the same thing that film studios do. Run indie substudios as an offshoot of your main studio, and use it to introduce new talented up-and-comers, as well as giving folk who are jaded with the mainstream industry and need some time out working on a 'labour-of-love' a break from the AAA scene. Give them the engines and tech from 2-3 years ago, and an A or B budget, rather than the AAA that everyone treats as the only alternative to indie. Let them make complex games - games with the complexity of the original Deus Ex, or Ultima Underworld, or System Shock 2; or games with the literary emphasis of Planescape: Torment; or games with the difficulty of Wizardry 4; etc.
With low budgets, they'd make money while updating those genres without 'dumbing down' or 'streamlining'. In the meantime, the youngsters and those who like simple games will still get the games that they like - except the quality of those may even be boosted, by having the side-studio system work as a means of giving talented young developers experience, that they can then take to the more simplified AAA projects.
That way everybody wins - we all get the games we like, and the studios get to make profits in both markets.
It works for film - why not give it a go here?
