Granted, the new MoS Batman will be very, very, VERY similar to Bale's Batman because that's where the money is.
I hope not. Over the decades, what's defined Batman is the degree to which he's been reinvented in different eras and adaptations. The Nolan Batman was radically different from the Burton/Schumacher Batman, which was very different from the William Dozier Batman (played by Adam West). In animation,
Beware the Batman is extremely different from
Batman: The Brave and the Bold, which was extremely different from
The Batman, which was somewhat different from
Batman: The Animated Series, which was hugely different from the Batman of
Super Friends and the two Filmation cartoon series. What makes a new version of Batman worth doing is the novelty of its approach, the addition of a new variation to the theme.
Copies are never as good as originals. If the new filmmakers just try to duplicate what Nolan did, they won't do it as well (even with Goyer involved in both, since the screenwriter has little power or control in Hollywood feature films). What they should do is what their most successful predecessors have done: break with the past and create a new Batman that's uniquely their own. That's what Burton did, that's what Nolan did, and that's what the makers of the best animated shows did. The one precedent we have for a Batman filmmaker staying close to what came before is Joel Schumacher, whose version of Batman was something of a hybrid of the Burton approach and the Dozier approach, and his films are regarded as the franchise's biggest misfires.
If they can get Bale to agree come back then MoS will take place in the same continuity as Nolan's Batman trilogy.
Probably, but that's not entirely guaranteed. There are cases of the same actor playing the same character in more than one continuity;
here's a TrekBBS thread listing a number of examples. Batman himself is such a character: Adam West has played him in several different continuities ('66 live action, Filmation animation, the
Legends of the Super Heroes comedy specials, and the later
Super Friends seasons), and so has Kevin Conroy (DC Animated Universe, Nolanverse
Gotham Knight anime,
Superman/Batman duology,
Justice League: Doom, and various video games). Noel Neill played Lois Lane in the '48/'50 Superman serials and reprised the role on TV with a different Superman. Judi Dench has played M in two separate James Bond continuities.
And then there are cases where actors have appeared in multiple incompatible sequels to the same original work -- Christopher Lambert in the various
Highlander sequels and the TV series, Don Adams in two
Get Smart reunion movies and one revival series (and Barbara Feldon in two of the three) that were all mutually incompatible, etc. Although I guess those don't quite count because they all branch off from a common origin.
I'm not sure if there's ever been a case where the lead actor from one movie series has played the same role in a separate, rebooted one, though. Maybe some of the Universal monster actors who appeared in Abbott & Costello films? Not sure that's the best example.