I do think President Kalam should continue for a second term. He has done a fantastic job - not just as a person to project India to the world, but also to expound his own vision. He also held his own on the face of political pressure, and this is why, I presume, the powers that be dont want him to continue.
In the rather sad circumstances when he does not continue, I think Narayan Murthy will be a great president. Mr. Murthy also has own mind, and a vision for India. He is known and respected in India and abroad. He has clear views on key issues - like social and economic equality and environment. He has been a model citizen, and a model businessman. I dont see the reason why other people feel that since he does not have a Ph D, he can't be the president.
I am not saying that Mr. Murthy is the only deserving candidate we have. There are indeed others. However, the usual political appointees always corrupt the office of the president - remember Gyani Jail Singh - and isn't a good idea. I guess if we are not talking about Mr. Murthy, we are probably talking about N D Tiwari, or I dont know who - Sharad Pawar, perhaps [I am only joking]!
So, my vote [I dont have one on this, still] goes to Prez Kalam, and if not, Mr. Murthy.