Motion Blur Lab Pro for Photoshop enters a release version creating complex realistic motion blur effects right in Photoshop using motion vector algorithms. Looks to be Windows only at the moment, and only for the Windows Photoshop 32 bit version. there is a free download for the demo version of MotionBlur Lab Pro that can be found here, I was unable to find any information relating to the cost of a regular license.

MBL PRO (Motion Blur Lab PRO) is a Photoshop® compliant plugin capable of producing high-quality, multi-directional and variable-strength motion blur effects quickly and efficiently using motion vectors. MBL PRO was developed in an effort to achieve effects not currently possible with virtually any existing digital retouching software and it is of special interest to professional photographers, retouchers and digital artists everywhere.