TOS has an episode that is basically a rehash of The Forbidden Planet. I actually like the modern 'The Day the Earth Stood Still' a lot more than I did with the original. I always thought that the original actor was so wooden that in comparison even Keanu Reeves in the new film seems charismatic. The whole nuclear aspect of the original wouldn't have worked today - it just is no longer the most pressing danger to our civilization. All in all The Day the Earth Stood Still was a much better remake than War of the Worlds (a crap film that was a remake of a crap film that shared little with the Brilliant novel beynd the title).
In all honesty I don't see that the concept of Forbidden Planet is anymore dated to the 1950s than Trek is to the 1960s. Unlike many 1950s sci fi this is not a bug eyed monster comes to Earth, threatens the little children and gets defeated by the all american hero film, Forbidden Planet is set in the Future with an alien planet and a star ship. As I have said it could be Trek, just change the shape of the star ship and the style of the uniforms.
Also it is years since I have caught Forbidden Planet on TV in the UK and for some reason it does not seem to be available in Region 2 DVD! So I welcome the remake as it may well stimulate a re-release of what must be the best pre-Star Trek sci fi movie of all time on DVD, or at least encourage one of the TV stations to show it again.