In the US it's pretty much the norm now to find "unlimited" connections (which are the norm) from all major players to be capped at ~250GB. Despite this, average broadband usage in the US is roughly 20GB per month. Predictions from various sources predict this will hit ~60GB by 2015. This figure still represents the average user using 1/4 of their monthly cap.
Here in NZ estimates seem to put the average monthly usage at somewhere between 10GB to 15GB now. Nobody I've spoken to seems to have an accurate figure of what this is, but it's safe to say it's doubled from the ~6GB that was talked about around a year ago.
Sure we have plenty of people using 60GB + per month. I know people who use 100 GB + per month, but getting back to averages I fail to see how the average NZer's use of the internet is being hampered by caps.