Not at all impossible from a technical point of view, but I am not sure that it is that likely to become the norm. For one thing very few actors retain legendary status & remain box office gold after they die. For example, as Arnie & Sly get older fewer and fewer people will be interested in seeing them in action films and fewer and fewer people will associate their names with Action Hero. They are already eclipsed by younger actors who can do anything they did and in 20 years time only a certain older generation will remember them, and the next generation of viewers & film-makers will regard them as history if they have even heard of them.
Humphrey Bogart is quite rare in retaining some of his status by virtue of belonging to an era where there were relatively few "stars" - plus in a field of very few stars, he was one of the bigger names. The field of competition widens as time goes by (see what I did there) and fewer if any actors are likely to stand out as icons 10 years or 50 years after their deaths.
In short: the ability to re-create an actor & voice is one thing, but re-creating dead stars will probably remain a gimmick rather than the norm. Rather it will be used to make better special effects & stunts for new actors.
Consider, though, the amount of money that's to be made in ruining franchises. Look at Star Wars and (though I'm not entirely in agreement on this one) Indiana Jones. Nostalgia is a big, big factor these days. Everything is a remake or a reboot, with millions going into CG in order to accomplish it. Want Optimus Prime in full realistic animated form? It can be done, and you will draw the kids who watched Transformers (not me, though I did love the show) as well as a new audience (my six year old nephew).
Now imagine they made a prequel to Indiana Jones, all done with the same style and with a young CG Harrison Ford. Or if they dabbled in the (extremely silly and unecessary IMO) Star Wars EU. You could have a sequel to Return of the Jedi with actors fully intact as they were in 1983.
As for the Bogie example, well I'm a fan obviously and it's just something I'd check out. I reckon that we'll be dealing with 'golden oldies' Brad Pitt and George Clooney by the time the technology is sufficient to be indistinguishable from reality.
Yes, few actors remain significant to the 'general public' once their peak is passed. Good examples of this are the likes of Jean-Claude Van Damme, who was once ahead of Arnie. He probably won't get the CG treatment, but James Cameron's Terminator 3 (the real one) with 1992 peak Arnie? Who knows.
AND for games, which was the original point of discussion: there would be absolutely nothing to stop them from making a game that feeds into your subconscious like a movie does. I know, gamers already experience this, but think of your parents and your baffled non-gamer friends who'd shun Mario, but would scream about who Keyser Soze is at a T.V. screen. L.A. Noire is already moving in that direction, and for current gen it looks amazing. They will usher in the end of the HUD. There will be no more 'dialogue trees', no Fallout-esque blank faces staring back at you...