The other is J.J. Abrams' reboot of the Star Trek franchise, with a prequel taking place at the Academy. The first real trailer has been released for the film, and it is...breathtaking:
Now, I know purists of TOS (that's The Original Series, for those not familiar) will no doubt have significant issues with several of the elements in this trailer (the Enterprise being built on Earth? Spock as a violent Sylar-like combatant?), but this looks freaking awesome.