I think crossplay for D3 would be a great idea. I just want to play on pc with my friends who are on ps4. The pc version of the game looks so beautiful and the mechanics are great, compared to the console version. I hate the fact that on a console if you have more than a few orbs lying around, you start to get fps drops. It just ruins the experience. I think the FOV is also a little to low. And that the ps4 fan goes mental every time I run the game. I know it will be a hard, maybe even impossible task to complete for D3 but I also think it will make a lot of players happy and make the community more connected.
Pve only sure. Pvp (in all games) on console are bad enough with mouse/keyboard adapter users, bringing in pc players without a bulletproof way to restrict m&k users from playing with controller users would ruin everything.