: Comcast is pursuing in its migration to digital full-throttle: The company began what it calls "Project Cavalry" back in 2005 (some markets, including Chicago and Philadelphia, have already undergone the transition). Once the migration is complete, customers must have a set-top box for every TV in the house (either a fully interactive box, or what Comcast refers to as a "digital TV adapter") to receive Comcast's cable channels.

Comcast doesn't expect to complete its systemwide transition until the end of 2010, and probably on into 2011. "It's a complete coincidence that the government picked a [DTV transition] date that happened to be in the midst of our Project Cavalry," says Derek Harrar, general manager of video services for Comcast. Comcast's digital transition does not affect the 20 to 30 channels of broadcast and local programming, which is "why we're comfortable with saying there's no impact, because [this project] has no impact on the broadcast channels."

Comcast isn't charging extra for customers to go to an all-digital starter level of service. They'll be able to rent a full set-top box, with video-on-demand and two-way communication between the box and Comcast, for $7 a month. A bonus for subscribers with multiple televisions in the home: All customers, including existing digital-cable customers, are eligible to receive two free one-way converter boxes. Called a (DTA), the box transforms digital signals into analog. The DTA thus does for expanded basic cable channels what a DTV converter box does for over-the-air broadcast channels.

: Cox isn't going all-digital at this time. The company will continue to offer a strong lineup of analog channels, which means minimal to no impact on your current setup if you don't have a cable box. A spokesperson says that Cox believes such a lineup will help sharply differentiate it from competing cable companies. According to Cox, the signal will actually be down-converted from its digital format, meaning that consumers will receive both over-the-air digital programming and some digital cable programming in analog format. On Cox.com, the company states its position explicitly: "For at least three years after the June 12, 2009 deadline, Cox will continue to offer analog broadcast signals to customers who do not receive Cox's digital services."

: Time Warner plans to use switched digital to free up bandwidth. A spokesperson notes, "We are generally migrating only a couple of our markets to all-digital (New York and Los Angeles), and in some cases only parts of those markets. At this time, we don't have any plans to migrate the rest of the country." But the spokesperson adds, "It's not hard to see a world where everybody would be all-digital." Some 67 percent of Time Warner's customers are already are subscribing to digital packages; the company didn't say what number of those customers already have boxes. Time Warner charges $7 to $9 per month for its set-top boxes, depending on the customer's location and on the type of box. If you live in an area where Time Warner has gone all-digital, you'll need a box.