Never saw this type of drivetrain before, but I think the intent is to have two modes: one where the DT is basically a H-drive, and another mode where the direction of the strafing module is your forwards and backwards, and the omni wheels on the side rails are used for turning about the traction wheel.
This is getting somewhere, but there are some issues with the strafing module. The first is the placement of the pistons: from the image, it looks like the pistons are going to prevent mounting the drive motors to the gearboxes.
This also reminds me of something I made in the past (link is here:
http://www.chiefdelphi.com/media/photos/42457)
The way I mounted the pistons on the wheel pods were questionable, for if the robot were to be hit on the side, the shaft would wear and even bend after a few rounds of pushing and shoving, and the pistons wouldn't probably last too long. The DT you made may have a similar issue, so I'm thinking you can fix that problem by having two face-mounted pistons, perhaps using a smaller stroke, and these two basically push down on the module rather than be mounted by a clevis. This way, the pistons won't witness much of the impact force in pushing matches.
Otherwise, this DT is looking good, and do try to improve on this: I'm pretty curious myself where progress on this goes, especially because I've never seen this type of drive before.