More efficient computers will mine more bitcoins in the short run, but not any more in the long run.
Even if it is extremely efficient, it is probably a lot easier to just trade for bitcoins.
beside, the point of bitcoin is not generating bitcoins. In fact, generating bitcoins does nothing to create any value. Bitcoins become more valuable when you can trade goods for it.
Some guys get more chance at making the correct calculation that get him new bitcoins. Big deal. He get to buy 50 bitcoins worth of stuff. That's not a lot considering the exchange rate. Maybe it's 4 dollars at most. Don't forget that it won't be 50 bitcoins forever everytime you solve a problem. It will eventually be reduced to half and then half until nothingness years later. 21 million bitcoin limit. No more can be generated.
Maybe it will be more rewarding to generate bitcoins when bitcoins are in extremely high use, but that mean more competition for mining bitcoins. All that does is increase the difficulty to the point of becoming unprofitable.