Yes, Sirius Satellite Radio (NASDAQ:SIRI) matters again. The stock closed yesterday at a level last seen 30 months ago. If you go by market cap, given the stock's unfortunate habit of speed-printing new shares, the company has never been valued as high as it is right now at $5.5 billion. Yet if things pan out just right, the stock will be worth every penny.

I've already waxed positive on the stock more than a few times this year, and you are more than welcome to revisit the reasons for my optimism if you wish. While it's true that David Gardner and the Rule Breakers team successfully shorted the stock at $6.90 back in January 2002 and profited from its slide all the way down to $0.93 a year later, I believe that the fundamentals have improved smartly since then.

The migration to satellite radio is real. Sirius and rival XM Satellite Radio (NASDAQ:XMSR) will be signing up a million new subscribers this quarter alone. Attractive deals with automakers are making satellite radio receivers a popular factory-installed option in more and more cars, and now the content is coming.

While Sirius is still behind XM on the subscriber count, it's holding a strong hand for the future after landing the NFL and then Howard Stern. The Stern deal is what is truly promising as he will be heard exclusively on Sirius come 2006. If just 10% of his free radio listeners make the move to Sirius to tune into Stern's rowdy morning show, it will be a profitable move for Sirius.

While a bullish initial stock rating from CIBC World Markets helped the stock last week, more than a few Sirius watchers will be tuning into David Letterman's The Late Show come Thursday. Handcuffed by Viacom (NYSE:VIA) when it comes to pimping his deal with Sirius on his Viacom-owned radio show, Stern has already told his listeners that his stint on Letterman will be like an infomercial. The fact that Viacom also owns CBS will make this very interesting for more than just the potential for verbal fireworks.

If Stern ruffles enough feathers, it may be quite possible that Viacom and Sirius would negotiate an early buyout of the Stern show. It's not what either party would want, as Sirius could use another year of milking the publicity to shore up its user base before committing to its $100 million annual contract with Stern, and Viacom would hate to lose a money maker who rules the critical morning drive radio market.

However, if free radio is going to become a casualty of the satellite radio revolution, there may be no better time like the present to get it started. If Stern's mouth proves to be the equivalent of the assassination of Franz Ferdinand, history may write a new chapter come Thursday. As the early adopter columnist in our new Rule Breakers research newsletter, I couldn't be more excited.

What will satellite radio mean to free radio? Can a television appearance really shape the future of radio? All this and more -- in the Sirius discussion board. Only on Fool.com.

Longtime Fool contributor Rick Munarriz thinks that XM and Sirius will defy the cynics and the skeptics over the coming years and he only hopes that they learn to treat their income statements and balance sheets a little better. He does not own shares in any of the companies mentioned in this story. He is a member of the Rule Breakers analytical team.