Harmony Technology breaks the lock-in that has been a leading factor in the success of the Apple iTunes Music Store. The iPod outsells other players by a wide margin, and iPod customers have been forced to use Apple's online music store because the iPod supports only the company's Protected Advanced Audio Coding (AAC) format. Now iPod owners will be able to purchase music from the RealPlayer Music Store, which uses a much higher-quality format--192Kbps RealAudio 10 AAC.

This should be fun to watch.
Cause Real didn't break just Apple's DRM, they broke their business model. After all, the whole reason to keep Fairplay proprietary is so that only music purchased at iTunes plays on the Pod *and* the only place iTunes music plays is the pod. Which means: lock-in. Once the pod people have enough invested in iTunes music files, they will have no choice but to buy ipods to listen to it. But Real's process involves downloading the music to the PC in Real-format AAC which is then converted to WMA or Apple AAC/Fairplay. The purchased file apparently stays in the neutral format. Hence, no pod lock-in for music purchased from Real.

The article states "iPod customers have been forced to use Apple's online music store because the iPod supports only the company's Protected Advanced Audio Coding (AAC) format." This is untrue.
The iPod supports MP3 (32 to 320 Kbps), MP3 VBR, Audible, AIFF, WAV and Apple Lossless audio formats in addition to AAC (with and without FairPlay DRM). I find it in poor taste that technolgy news writers (not just this one) mislead their readers with such mis-information.
Because of such reporting there are many people who believe that iTunes can only work with the iPod. iTunes can work with a wide array of portable digital audio players that support MP3s.
The limitations and lock-in have to do with FairPlay managed AAC files sold through the iTunes Music Store. There are ways around this however.
Of course you already knew all of this.