LOS ANGELES -- The Cable Show -- Insisting that pay TV companies are adding new customers, Comcast Corp. (Nasdaq: CMCSA, CMCSK) CEO Brian Roberts attempted to debunk reports that more consumers are cutting the cord on their cable TV subscriptions and relying solely on the Web for their video entertainment.

Roberts, speaking here today, supported that notion by noting that public cable operators, satellite TV firms, and telephone companies that reported earnings within the last two weeks added about 500,000 net new subscribers combined in the first quarter.

“There’s not any real evidence that [consumers] want to get rid of my distribution, whether it’s satellite, cable, or phone, and just go to the Internet,” Roberts said in a Q&A session with former News Corp. (NYSE: NWS) president Peter Chernin.

But the Comcast chief said that he has expressed concerns about cord cutting, and noted that he has had previously expressed more alarm about the trend than one of his top lieutenants, Comcast COO Steve Burke. (See Boxee CEO: MSOs Should 'Go Over-the-Top' and What Fights Cord-Cutting?).

“This is where Steve Burke and I are very different people. He wakes up every day, and the glass is half full. I wake up every day and the sky is falling,” Roberts said.

Roberts said Comcast is focused on developing product that will allow it to reach viewers on devices ranging from mobile phones to 150-inch widescreen TVs, pointing to the company’s TV Everywhere product, Fancast Xfinity TV. (See Comcast to Expand 'Xfinity' to DSL Subs and Comcast's 'Xfinity' to Go Mobile in 2010 ).

Comcast, which began offering Xfinity on a national, but beta, basis in December, allows customers to access content from dozens of networks in their cable subscriptions online. It also plans to launch a new, supposedly easier-to-use version of its TV Everywhere product within three months, according to Roberts. He said the authentication system involved in the first effort, which required subscribers to verify that they were paying Comcast subscribers, and to download new software, was too complicated.

“There are too many steps. We’ll have another version out in the next 90 days or so that will make it easier and easier. I think we’ve made real progress. Would I like it to be faster and more ubiquitous? Sure.”

Roberts used his appearance to tout Comcast’s plans to expand the number of movies in its video-on-demand (VoD) menu by 450 percent. Its systems in Washington and Philadelphia will soon be the first to get an additional 9,000 titles, Roberts said. Comcast claims it's able to expand its VoD library through a new storage and distribution system -- it didn’t detail the gear that it will rely on for the expansion. (See Comcast VoD Choices Hits 25K.)

Even though Comcast only passes 24 percent of US homes with its cable systems, Roberts boasted that the company generates more traffic through its VoD platform than Apple Inc. (Nasdaq: AAPL) does through its iTune store. Comcast VoD subscribers have viewed more than 1.5 times the amount of content that has been downloaded on iTunes in the “last few years,” Roberts said.

Comcast has exceeded 15 billion orders to various VoD shows, and it now counts about 350 million on-demand views monthly. The average Comcast customer that uses its VoD platform uses the service 20 to 25 times per month, Roberts said.

Also worth noting from the talk Roberts had Tuesday with Chernin at a brunch hosted by the Hollywood Radio & TV Society: