Imagineer Systems, makers of popular planar tracking software mocha, have released a new training video with product specialist Mary
Poplin, comparing mocha with the new Adobe Mask Tracker. The Mask Tracker works by drawing a mask and then telling After Effects to track the area within the mask. Mary discusses many of the pitfalls and limitations in the new Mask Tracker; however, it is also pointed out that the tool works adequately for tracking some objects, mainly rigid surfaces.
My personal conclusion is that the Mask Tracker is a quick-and-dirty, yet inflexible, tool for simple planar tracking tasks with limited movement. Despite its limitations, however, this may be a tool with yet unrealized potential and one that Adobe may develop further.