You really don't need anyone's permission to participate and share your cover artwork.

if it's good, people will use it for their covers, if it's not so good you'll get comments on how to make it better and so on. In my view, it's all about taste and what YOU would like to have on your own covers, then share it.

Either way, Adywan will provide (I'm guessing here) an "official" cover and DVD art with the release like he did with ANH:R. That by no means you have to print. I did because I loved them, but I'm also working on my own and if I think they're good enough to share, I'll just post them.

It's all about contributing to the community, in one way or another IMO.

:)