Its the same goddamn story each and every time, censorship in the name of the children: "Please, won't someone think of the children!".
Now that Craigslist has caved in to pressure, its only a matter of time before the site becomes a sanitized, worthless copy of ebay. First its the adults services, then the RIAA and MPAA will successfully lobby some congressman to come down on Craigslist to shutdown any DVD and CD sales. Book publishers will demand craiglist stop the sale of books. Car manufacturers will demand craiglist ban automobiles. Labor unions will demand craigslist ban handyman/craftsman type people from selling their services on the internet.
Mind you, none of these things is illegal, but now that Craiglist has proven themselves a push-over, the right people will be able to deman everything from them. This is why everyone fought against porn filters and the .xxx domain (porn producers and others alike). Because once you open the floodgates, you can't close them again.