Allow the exporting of animations as image sequences. Could be useful for VFX professionals, or integration with other software that expects image sequence input. Would also allow easy development of distributed rendering, as the final video file would not need a build phase, as each frame would simply be placed into the render directory.
Image sequence format examples: JPEG 100%, PNG, TIFF (very large files) DPX, OpenEXR.
Numbering conventions to be stipulated by hash marks:
foobar_####.jpeg = foobar_0001.jpeg etc