Mine is essentially flawless but I intend to use a case with it just to be sure it stays that way. I've bought a cheap silicon case for now. I'll buy a nicer case when all the manufacturers have their new models out.
As for this poll, I think we should take it with a massive, MASSIVE pinch of salt.
First you have a self selection bias. People with no problems with their device are far less likely to click on this thread and take the time to vote. This is a massive bias problem which happens with any self selected group. A better method would be to go and contact 2000 buyers and ask them each the question. That would eliminate this bias.
Secondly you have the issue of lack of evidence - how can we be sure that all those "damaged out of the box" reports or even the scuffed reports are true? Macrumors is filled with anti-Apple trolls. Would anyone here put it past them to click on that option just to skew the poll and give them some new ammo to attack Apple with? Also we have no idea how those who have scuffed their devices have treat them though that's a lesser issue if all we wish to learn is the overall instances of scuffing.
Thirdly you have the main problem - the sample is far too small. Apple saw 2 million pre-orders on day one. We should assume that about 4 million iPhone 5 devices are now in use. You've got less than 2000 votes here. If we assume that 3 - 3.5 million of those pre-orders are the black model, the sample here is almost vanishingly small. Certainly not large enough to diminish the impact of self selection bias and dishonesty which will skew the poll.
We might be able to, at a very, very rough estimate, say that between 2-20% of black iPhone 5s have suffered scuffing either in the box or within the first couple of days of use. It could be much lower, of course. I suspect, if it is a wide spread issue, we'll hear about it more widely in the mainstream news media.
As a side point re. the general question of robustness, arguably the iPhone 5 is a step in the right direction. Drop tests have shown that the iPhone 5 fairs very well compared to phones like the Galaxy S3 in terms of real, structural damage. It's clearly far more robust than the 4/4S when it comes to withstanding impacts. It is, however, likely more vulnerable to scratching and scuffing on the chassis if not on the front panel. So it's tougher in one sense - you're far less likely to render this new iPhone unusable than the last model, but that comes hand-in-hand with a greater chance of minor cosmetic damage. I guess that's a decent trade-off all told.