If we do find a habitable planet then sure, no reason not to send some people there, it would be interesting if nothing else. I don't consider Mars to be habitable though, it's the closest other than Earth in our own solar system but that's not saying much. The biggest problem with other possible candidates is that it will take multiple human lifespans to reach one even if it is found. Much of science fiction relies on the possibility of faster than light transport, but I just don't see that happening. It's roughly in the same realm as over-unity stuff.