Wow that is a tricky one, I suppose you’ve almost answered that in your own question in that if intelligence is infinite, it doesn’t have a limit! It depends how we measure intelligence though. But I do think as humans we will always limit the robots in some way so that we always stay the masters!
I think one of the things that it is very difficult to “teach” robots is creativity and thinking outside the box. So you can give them a job to design a robot, but they will never be really ingenious about it as they can only “think” within certain constrained parameters. So the human element is always going to be important, in my opinion. So I think yes we can make robots almost infinitely intelligent, but that’s not the same thing as being creative, or having common sense, or being innovative.
This question started a really great discussion earlier on between some of my coworkers! There is the opinion that robots cannot be more intelligent than we are as they would need input from us humans and therefore are taught by us. The other opinion (I’m supporting) is that robots will be able to be more intelligent as humans once we have the computing power (which will also take some more time) as they can compute all the possible solutions and optimise these. They could theoretically build other more intelligent robots (Ohh.. that sounds really dark, sorry! These assumptions are definitely not going to happen in the next few years – it will take more than several lifetimes!) BUUUUT I think robots will never reach the emotional level that humans have and this makes us superior to robots!