From http://a.longreply.com/109511:
We will introduce a 100 GB Road Runner Turbo package for $75 per month (offering speeds of 10 MB/1 MB). Overage charges will be $1 per GB per month.
OK, 10 mbit / 1 mbit is a pretty decent upgrade for most people. And I'm assuming that even moderate torrenters aren't doing a whole lot more than 100 GB / month - this is 3 GB per day!
Overage charges will be capped at $75 per month. That means that for $150 per month customers could have virtually unlimited usage at Turbo speeds.
Ah, so here's how it works. You keep paying per GB, up to a max of (plan rate) + $75. If you're using less than 100 GB / month, you're getting a nice bandwidth boost (admittedly with a cost increase you didn't ask for). If you exceed that, you'll be paying up to $150 / month.
The key thing here to me is the upload rate - you'd be paying a real premium for 1 mbit up under current plans. If you don't care about upload, of course, you're basically getting screwed, but I don't think it's as bad as a lot of people are imagining at first glance.