Yes, there're drivers clustering right outside the arrivals area: I don't know about your particular destination, but say you want to go to Shenzhen and somebody will certainly sidle over. These are private drivers, not registered taxis.

Dealing with these guys is not pleasant and who knows if you'll be left stranded mid-route if you refuse to pay an increased fare demand. Myself, I felt uncomfortable enough dealing with them that I finally just decided to stay in Guangzhou the night.