in a word... no
you see if they were doing this, and i stress that 'if' bit, but if they were the decision woul dbe based on factors out of our control, they would say OK we're hemmoraging money and therefor profits because of users who download 24/7 and really we only want the nice email crowd who might use a GB on a 3GB account per month, so why not cut the fat, get rid of the 24/7 type users and be back to profit in no time.
So if thats thier line of thinking, then you could have say 5000 users saying 'please dont do it WBS' but WBS will ignore it because 5000 light users make them more money than 5000 heavy users and a loss of all the users that download heavily (well heavily for WBS anyway) would clear up alot of problems on the network, like overcrowding and contention.
The last thing is they wouldn't need to constantly invest time and therefor money into thier custom software to throttle users, its much easier/cheaper to just cut off users than it is to throttle them, and I think WBS has had it with users finding ways around the throttle.
I could no longer use iBurst if this were the case, I do not want to take any steps backwards and thats exactly why I wouldn't go to something like 192kbit ADSL as it is. So if they were to implement this at the earliest it would be in August (although I'd like to think we'd have more notice than a week or so) and that means I just jump to 1mbit ADSL, for those who can't get ADSL..... I'm not sure what to say to you.
From my business mind I think that this is just loopy because even if it gets them back to profit fast it would make growth slower and give them a bad name (plus the contracts... well it would definatly be in breach) but knowing WBS and how they seem to not think things through and make changes overnight, it probably is a possibility. But we can't assume its true untill they tell us it is.