Since I was always much too far away to see anything, my only impression was that it was very disorienting not to be able to see the WTC, a lot more than I had expected. Between the WTC and the Empire State Building, I always knew where I was in NY in relation to anything else. Without the WTC there, and considering my limited knowledge of the other buildings in downtown, I found myself getting confused as to how far downtown we were. But other than that, numerous missing person fliers pasted everywhere, and the massive proliferation of American flags on almost every thing that could have a flag attached to it, things seemed exceedingly typical.
Talked to my Dad again, and he was in very good spirits, which is good. I'm sure he'll be just fine, the recovery period is just going to suck (as it would for any major surgery). We'll probably head down to North Carolina to see them some time in November (maybe Thanksgiving - might as well get some great food out of the trip :)