If DX2 doesn't ship with 2.3, I'd be surprised. DX1 is getting it's OTA here in the very near future and DX2's screen shots show it running GB. If it doesn't ship with it, it'll be an OTA real soon after. So don't let that be a factor in your decision.
I'm a DX owner, and I'm getting the E3D. Why? While the DX2 is a decent upgrade over the DX, I'm just tired of VZW's BS. They're tracking who takes updates in some odd attempt to track who is rooted. They're cracking down on wireless tether. I'm also not a fan of the nickel and dime things they're doing. Plus Sprint is just as strong in my area and are cheaper.
DX2 won't have LTE. Which can be both a blessing and a curse. Better battery, but slower speed. I don't know how LTE stacks against Sprint's 4G, but more importantly, how VZW's 3G stacks against Sprint's 4G, but perhaps that should be a buying decision.
Hardware spec wise, they're neck and neck. The E3D has the 3D part, obviously, but that may also be a blessing and a curse for the same reason LTE is. More battery consumption for a gimmick, at this point. You have to decide if that's worth it to you or not.
So that's why I'm going E3D instead of DX2. Well, actually, I was going to wait for the Targa that's rumored to come out at about Christmas...which is a DX2 with LTE (hopefully a second gen radio that's less of a power hog) and a front facing camera. Sprint seems to care more about their customers than VZW. The phone has 3D, with a toggle switch (I wouldn't even consider the phone if it didn't have that) and is beefy under the hood, so a solid upgrade over my X. Now if they were only to release an official release date and price, I'd be happy and pre-ordered already.