Comcast today gave their rebranded version of Clearwire Mobile WiMax service a new name: "Comcast High-Speed 2Go." According to a Comcast press release, the new service launches tomorrow in Portland. The "up to 4Mbps" service will launch everywhere Clearwire deploys Mobile WiMax -- a plan that should see nine cities live by the end fo this year. According to Comcast, the company is offering two different wireless data plans:

• Comcast High-Speed 2go Metro service costs $49.99 for twelve months ($72.95 thereafter) and comes with 12Mbps Comcast home broadband service and a Wi-Fi router. The service uses a Mobile WiMax data card that will obviously only work in areas where there's Comcast/Clearwire Mobile WiMax.

• Comcast High-Speed 2go Nationwide service costs $69.99 ($92.95 thereafter) and also comes with Comcast 12Mbps home broadband service and a home Wi-Fi router. The service uses a dual-mode data card that allows users to float between Clearwire's Mobile WiMax network and Sprint's 3G EVDO network.

You can of course compare this to standalone Clearwire pricing. Comcast tells us existing double and triple play customers will be able to add Mobile WiMax service on to their current bundles for $30 more a month. Comcast invested roughly a billion dollars into the Sprint and Clearwire joint venture -- and is buying bandwidth wholesale from the new operator.

Comcast’s wireless service won't involve voice product initially, though the carrier suggests that may change. As for caps, Comcast spokesman Charlie Douglas tells us that Comcast is "deferring to Clearwire's TOS on usage" while customers are connected to the Clearwire network. Clearwire's service comes with 200MB, 2GB and unlimited flavors, so we'll have to wait and see which "deferment" Comcast chooses. When connected to the Sprint EVDO network, customers are restricted to just 5 gigabytes of usage per month.

Of course Comcast's service will naturally suffer from the same problem that plagues Clearwire: a limited footprint and future viability in the face of AT&T and Verizon's LTE plans. In addition to the live markets of Atlanta, Baltimore and Portland, Clearwire's expected to launch eight additional markets in 2009, including Las Vegas (also already unofficially live), Dallas and Fort Worth, Chicago, Philadelphia, Seattle, Honolulu and Charlotte. Rural Comcast customers, or Comcast customers in second or third-tier cities probably shouldn't hold their breath.