I know this is really early and people will say why PlayBook instead of iOS or Android... but here is why it might work:
http://unity3d.com/union/
Since it is done in Unity3D it is quite possible for Eternity to exist in BlackBerry AppWorld. Unity people can convert Unity games so that the game work on other platforms (PlayBook, Roku etc...). The catch is that (as far as I remember) they get to keep the 20% and they want the game to be great (which Eternity will surpass)
So here are the games of Unity that exist in PlayBook:
http://appworld.blackberry.com/webstore/vendor/16944/?lang=EN
Also here is InXile's The Bard's Tale (the most important CRPG in the PlayBook) again in AppWorld:
http://appworld.blackberry.com/webstore/content/119547/?lang=en
I also think Obsidan can talk with the people at InXile about the money they make from the AppWorld and see if it makes sense or not...
And here is the specs to the tablet itself:
http://us.blackberry.com/playbook-tablet/tablet-specs.html
I know this is really a short post with not much information but I wanted to see if people (both Obsidian and non-Obsidian) are interested.
ps. this is my first post so don't be harsh.
2nd ps. I was hoping that they were going to use Unity when they first put up the Kickstarter, I have been working with Unity for 2 years on various project and it is great program to work with.