It says the rates go up in September. That is why your rates have yet to go up.
LP, I have cox cable modem in San Diego where this article is from and my service is only $30/month. I own my own modem though. $10 to rent from cox. Kinda blows though, I just bought this modem to lower my long term costs and they go and up the rate 50% of what I was going to save.:|