Each week Ross Rubin contributes Switched On, a column about consumer technology.

Before the iPhone's release, there were four major smartphone operating systems -- Symbian, Palm OS, Windows Mobile, and BlackBerry OS. And after the iPhone's release, their user interfaces all seemed dated in some way. Palm OS and Windows Mobile have essentially been replaced by new operating systems dubbed WebOS and Windows Phone 7. Symbian stakeholders, though, has decided that there is no need to throw out the past completely, and are instead looking toward a series of evolutionary upgrades to make the now open source operating system more competitive.

This week at RIM's WES conference, the company is announcing a similar evolutionary path for the BlackBerry OS. Like Symbian, the BlackBerry OS has a reputation for being fast and efficient but has not kept up with many of the aesthetic and input amenities offered by more modern competitors. The challenge will be to preserve what users love about the platform while disrupting it in many ways. For example, while the new BlackBerry OS will be better optimized for touchscreens, reports are that it will not require one.

"For all the talk about apps, a solid browser experience is still important to reach a vast array of web content still unavailable as apps for any smartphone platform. "
RIM is launching a multi-pronged plan to ripen the BlackBerry OS. Elements include replacing its browser with one using the same WebKit engine used in the default browsers of Android, iPhone OS, and WebOS. For all the discussion about the apps race that occurs, a solid browser experience is still important to reach a vast array of web content that has not been made available as apps for any smartphone platform. Another is enhancing the operating system to take better advantage of touchscreens after the makeover that has graced the BlackBerry Storm has proven unsatisfying. These improvements should include support for the kinds of "physics"-based effects, gestures, and transitions we see in competitors to BlackBerry OS. In addition, key RIM applications such as the e-mail client and the media playback application should also see upgrades.

It's no coincidence that RIM has decided to upgrade the BlackBerry OS in an evolutionary way similarly to how Symbian is being upgraded. Whereas Symbian has the highest smartphone market share globally, RIM has the highest share in the U.S. In contrast, Windows Mobile and Palm OS were struggling with low market share that begged a more radical approach. At least in the medium-term RIM's approach places its OS revamp lower in the risk-reward curve than Mirosoft's or Palm's resets. While RIM's significant enhancements may bring the BlackBerry experience roughly on par with the current Android or iPhone experience, it risks failing to create something beyond what competitors are doing. In contrast, Windows Phone 7's hubs and WebOS's Synergy architecture offer levels of integration that differentiate them.

Different doesn't necessarily mean better, though. RIM has been the most successful smartphone vendor by far at combining its own software into a portfolio of devices, albeit one anchored on the familiar Curve, Tour and Bold QWERTY candy bar form factors. As the market shifts toward touch -- either with or without physical keyboards -- providing a roughly on par experience that doesn't take big bets on motifs like social networking may a double-edged sword. RIM is taking on many of the user experience attributes that have helped create success for Android, but it may not be enough to defend against the multi-vendor assault of the Google-backed OS.

Ross Rubin is executive director of industry analysis for consumer technology at market research and analysis firm The NPD Group. Views expressed in Switched On are his own.