Customers in our Comcast forum note that the cable company appears to be bumping their top-shelf 305 Mbps down, 65 Mbps up customers to 505 Mbps down, 105 Mbps up at no additional cost. Comcast introduced the fiber-to-the-home powered 305 Mbps tier late last year to select customers, though the service will run you $400 a month, plus a steep ETF higher than $1,000, as well as a $250 activation fee and a $250 installation fee.

Comcast found itself bested in the speed marketing one upmanship last July with the announcement of a 500 Mbps Verizon FiOS tier. That tier costs $300 a month with a two-year contract, or about four times as much -- and half as fast -- as Google Fiber or the other municipal broadband options I was discussing earlier today.

While Comcast has been experimenting with caps as low as 5 GB, the company's 505 Mbps tier does not come with a usage cap. Comcast confirmed to me that all customers who can currently get 305 Mbps using Comcast's metro-Ethernet fiber to the home solution (and that probably isn't all that many) should see the bump shortly.

"We're increasing speeds for the existing Extreme 305 customers and your user is likely one of the first to experience it," Comcast spokesman Charlie Douglas confirmed to me in an e-mail. "This is our 12th speed increase in 11 years and reaffirms our commitment to deliver the fastest speeds to the most homes in the United States."