DxO has just announced DxO ViewPoint, a new piece of software aimed at fixing lens distortion in your images. Available later this month for $79/€79/£69, DxO ViewPoint will be released as both a standalone application and as plugins for Adobe Photoshop CS3 through CS6, and Adobe Lightroom 3 and 4.
Designed for use on images that suffer edge distortion from wide-angle lenses as well as perspective keystoning, the software can automatically apply the adjustments "while taking into account such shooting parameters as focal length and sensor size, and while respecting the image proportions, for a more natural rendering," and will automatically crop to the maximum size. Alternatively, there will also be advanced controls for manual tuning.
Both Photoshop and Lightroom have some level of distortion correction built in, so the proof will be in how much better DxO can do. If you want to see some samples, DxO has released a 155MB image pack with the press release that you're more than welcome to analyze.