Porting is not really the problem, quality assurance is. Though i will admit i dislike it when games get ported in such a way that they are not using a system to its full potential, im mainly talking in terms of defects and poor controls conversion.
Bethesda are a good example of crap quality assurance in its ports, the amount of crashes and defects in oblivion & fallout 3 on ps3 is way too high for console game, and their after sales (or lack there of) is laughable.
Another good example is the port of dead space to the pc, who would have thought we would see a fps on a pc with such poor controls & lack of flexability to change them after so many years? That was an act of excrutiating lazyness and poor QA on the part of the devs.
Understandable in the first wave of games for the current console generation that it was not possible, but 2-3 years into development cycles, really by now most of the games companies that make multi-platform games should have written/be writing high level libraries which negate the need for a significant porting effort. Which of course would utilise lower level libs that already maximise each systems potential.
So the message to the devs would be, spend those extra few weeks getting it right, stop rushing out the ports only to end up with bad reviews and loss of half your potential sales!