Firstly, it's remarkable that some liberals jump to the "but they're Arabs!" angle so easily when it suits them. With confidence I'll point out it's the "centrist" democrats, not the more liberal, that do this, but still, it is remarkable.
Personally, I believe the question is of great use to the republic and damaging to the Republican myth of nationalistic patriotism. Republicans, like us all in the modern world, practically, are internationalists after all. And to my way of thinking, even if the answer is, "well, it's fine for Dubai to own American ports", the question itself is important to sort through, not so much for we that already pay attention, but for the public. The public may be fine with it or not, either way it is suitable for there to be public knowledge about the policy, because port security is an issue somewhat crucial to the current public understanding of our national security in general.
I tend to think of things in terms of system design, and in matters of national security, if possible, and it is possible, I believe American firms should do the work. In truly sensitive cases the government itself should do it, so yes, that includes a preference for excluding British firms as well as Dubai ones, but especially in the case of state owned firms.
OTOH, I'm not apoplectic about it. Indeed, quite the opposite, I think the issue is full of valuable points and questions, deserving of public debate whichever way they are decided in the end. Too bad the public is so bad at debate (their leaders make it hard on them, but then, they don't have to follow) and that the debate degrades so quickly, practically before it's even begun.
One more comment before I leave it for now: I was surprised Bush was willing to threaten veto, even veto, in defense of the deal, I thought he'd back off quicker than a Nader voter at an Al Gore fan club meeting.