You may have heard that Wolfgang Petersen will be directing a movie tentatively titled "Batman vs. Superman." The characters will come into conflict before resolving it to team-up. They are currently seeking actors for the main roles.
Now this could be a good movie, but some things have caused me to be less than optimistic. These include the "films" Batman Forever and Batman & Robin, and also rumors from the last few years of what Tim Burton and Jon Peters wanted to do to Superman in an upcoming movie. Things such as thinking the Superman costume was "too pink," that he shouldn't fly, and that he should have "murderous eyes" and "the instincts of a caged animal." Doesn't give you much hope...
But, I'm going to try and be positive. Here are a few things that can be done to increase the quality factor:
First, stick to what works. The animated Batman/Superman Movie and their respective series seemed to be fairly popular. Paul Dini and Bruce Timm got their personalities right, and most people expect Batman and Superman to be that way.
As for costumes, look to Alex Ross' rendition for an example of how the classic costumes can work in the real world. And no, you shouldn't use rubber!
Which brings us to the second point: Adapt the comics, not another adaption. The Tim Burton Batman movies seemed to want to distance themselves completely from Adam West's version, and in some ways worked, while the last two embraced it, and failed miserably. The 60's Batman was translated from comics of the time and the recent past. Batman has evolved, so the movies need to as well.
Wolfgang Petersen has mentioned the comic series World's Finest. Hopefully he was referring to the great 1990 mini-series. If they stick close to at least the look and tone of that series, this could be really good.
Third, while this is being called "Batman vs. Superman" (at least for now, some have suggested they should call it "Superman/Batman: World's Finest"), I hope that the "blows" they come to are not at all literal, and that they are not long-lasting.
Lastly, make these characters people to be admired, and not a dangerous madman and naive fool. They are the world's first super-heroes, after all...