In all seriousness, it could be too late.
Arnie is more of an icon than an actor. In the past his movies have sold and been popular because of his appearance and his persona, rather than his acting abiity.
In the 80's and to a degree the 90's he could do no wrong. All you needed was a poster of Arnie holding a big gun and looking cool and you could sell the movie and make a profit before you had even shot a foot of film.
And during the video era and pre-internet days, it was easy to get away with that sort of thing. But then everyone started doing it, other 'action heroes' muscled in on the action, and the whole thing became such a tired old cliche...big muscle men with guns looking mean, overblown action sequences and the obligatory 'witty' quips from the hero.
And I think the public largely tired of it, plus Arnie was getting old and his movies were not selling as well...I always felt he 'retired' at the right time.
I really don't think it will be easy for him to go back to movies. And if he does, will they go the action blockbuster route, or the comedy route?
The first one is risky, because a lot of money neeRAB to be invested if they are thinking of a 'True Lies' or 'Terminator' style vehicle...and there is no guarantee of a return on that sort of investment, we don't know if the public are interested in him the way they once were.
And as for the comedy route...well, I know he had a few successes with movies like Twins and Kindergarten Cop - but then there were real clunkers like Jingle All The Way, Junior and Batman and Robin.
Personally I feel he got out of the industry at just the right time, his popularity was waning and his movies were not doing that well. It seemed the smart move at the time. And I'm not sure that the public are clamouring to see another Arnie movie...but in this industry, I guess you never know.