The planet in the alpha centauri system may be in tidal lock, and so have a cooler far side. However, it has also been suggested that systems with this type of planet often have other similar small rocky bodies further out as well, so there is still hope for finding another earth-like planet
Having said that, Mars is fairly earth-like, and all we've sent there so far is robots
It may not be in the habitable zone – but it's a really cool discovery.
A habitable planet in Alpha Centauri would have been nice. Not that I would experience even a drone landing there in my lifetime, but it would be good to know that there is a realistic option for mankind to reach another planet. ^^