tedster - 8:44 pm on Feb 23, 2011 (gmt 0)
In this case, I'm not so sure that it would be a crawling problem at launch. But since the pages are real estate listings with a significant churn, you will want to be sure that you handle their removal very cleanly - ideally with a 410 Gone header. Otherwise crawling problems may evolve over time. I'm working with a parallel case right now, and they have a nice PR5 home page.
Just because I said it won't be a problem, that doesn't mean that I see any significant advantage, either. Those kind of listing pages are more for the visitor than the search engines. It's hard to get the URLs to stay in the index or to get even long tail traffic, because so many other sites will often have something nearly duplicate. The vertical is jam-packed and Google appears to have an almost standardized ways of ranking individual URLs - or should I say NOT ranking them ;)