I also made a video about uncharted 3 going free to play cuz i want more ppl to download it here it is, some uncharted 3 gameplay with commentary: https://www.youtube.com/watch?v=DLfIrtOxA4A&feature=youtube_gdata_player
It depends on the match type. In FFA, you might see 2 to 4 of them. In TDM, you might see a whole party of them.
It is certainly enough to freshen up the average skill level of the player pool IMHO.
from playing Classic mode for a few hours for the past two days I've encountered probably about 1-2 non-paw players every 4-5 matches. I'm just happy I can get into a Classic mode game. A few months ago I gave up because it would take 20-30 minutes to get into a game if I didn't give up in the first place.