Yes and no.
At the moment to keep the system stable isp's are probably having to operate with a much lower contention ratio, probably around 8 to 1. This is obviously meaning they are running at a loss, but once more average users start signing up they should be able to stretch it out to atleast 20/1. At that point they should become profitable.
Internationally adsl contention ratios range from 20/1 to 50/1. The one thing we mustn't discount, is how little some users use. The big problem going forward is going to be how to get these users to upgrade to uncapped because many of them will be happy to stay with a 3 gig account. It's gonna be tough, but it's not impossible.
http://en.wikipedia.org/wiki/Contention_ratio