BlackBerry-maker Research in Motion has seen its market cap shaved by 17% in the last six days as a trio of Wall Street analysts has raised doubts about the company's prospects going forward.

After closing at $122.08 on Nov. 29, RIM's share price sank to $100.96 Wednesday.

The slide began on December 1 when Piper Jaffray analyst T. Michael Walkley cut his earnings forecasts for the company, citing "mixed demand for smartphones and data-oriented devices across all four major U.S. carriers" and "a discernible deceleration of sell-through trends" for the popular, consumer-oriented BlackBerry Pearl, which was introduced in September 2006. On Monday, Morgan Keegan analyst Tavis McCourt downgraded the stock to Market Perform from Outperform, mentioning a potential drop in demand from the imploding financial sector. And Tuesday, Peter Misek of Canaccord Adams wrote about "a potential slowdown in momentum" for the smartphone giant and dropped his own earnings forecast.

In a sense, this is a normal correction for a stock that had appreciated by around 70% since June, and all three analysts hedged their predictions with continued positive outlooks for RIM, which now has more than 10 million BlackBerry subscribers. But the ground in the wireless business has definitely shifted over the last two months, and RIM is faced with some intriguing challenges over the next two years.

The most important change is that the wireless and mobile industry is evolving toward an open environment that directly contrasts with the end-to-end, proprietary BlackBerry model. The announcement of Google's open-source Android platform for mobile devices, Verizon Wireless' decision to open its network to third-party devices and applications, and the upcoming FCC auction of valuable spectrum in the 700MHz frequencies all point to a world where users will be able to select from a buffet of devices, networks, and services rather than the fixed price BlackBerry menu.

Analyst Carmi Levy, senior vice president for strategic consulting at AR Communications Inc., believes that RIM, which currently dominates the high-end enterprise smartphone market in North America, could be headed for an Apple-like niche status, while the rest of the world moves toward open standards and open networks. Not that that's a terrible thing.

"Even in an increasingly open wireless world, there's ample room for a proprietary solution that just works," says Levy in an email.

And it would be a mistake to think that RIM will fail to adapt and compete in an open wireless environment. The company already pushes its BlackBerry Connect software, which can be used with devices from a variety of handset makers running on the Windows Mobile, Symbian, and Palm operating systems. And RIM has shown itself a formidable front-runner, padding its lead even as newer entrants unleash a stream of innovative new devices with BlackBerry-like capabilities.

The Great Opening of the wireless world, says Levy "is no more or less onerous to RIM's future than any change it's faced, and addressed, in the past."

Still, an Apple-sized slice of the smartphone market is not likely to satisfy outspoken RIM co-CEO Jim Balsillie. It'll be interesting to see how the BlackBerry maker responds to the latest challenge to its leadership.