i just though of something

Back to the OP comment.

They might do what borderlands did with its DLC
Allow the player to see, pickup, and examine the items if another player drops them, but require the DLC for use.
Worked wonders, and got me to by the content. Nothing like your friends showing off their level 61 gear that outdoes anything you have by a longshot to make you want to pay more money.

I actually think that would be the smart things, might even cost more money not to do this. They'd have to program a way to split people with and without the DLC, and since this game doesn't sound servers...Yeah, it sounds hard to do

You should be compatible to play with everyone once the PTD console version comes out even if the DLC isn't yet. Likely there will be a patch which adds all the content of the PTD edition, but access to any of the content it only available once you purchase the new DLC. This allows people on different version of the game to interact.

And probably drop each other stuff, unless From specifically adds something to stop that, and looking at how From handles online play I doubt that will happen.

I don't mind paying for DLC on a game that I already enjoy, because I know its going to add more enjoyment and replay value to something I already like.

If I don't like the game enough as it is, then I would not pay for any DLC. An example being Call of Duty, I would never buy a map pack for those games because I don't even enjoy that series.