It probably will support native code, but will have certain restrictions for security.
If anyone's ever worked with "stackalloc" in .Net, you will be able to allocate and free memory (and use pointers) but if you try to go outside of the allocated memory you get a standard exception and the program exits.
There are many ways it can go but I doubt they will have a native SDK for PlayBook, then bring the OS (or at least the best parts of it) over to the phone side and prevent the native SDK from being used.
------------------------------------------------------------
Three simple rules:
1. Please use the search bar before making new posts.
2. Kudo posts that you find helpful.
3. If a solution has been found for your post, mark it as solved.
--I code too much. Well, too bad.
Projects:
Bing 4 BlackBerry: http://bbing.codeplex.com/
PDF Renderer 4 BlackBerry: http://pdfrend4bb.codeplex.com/
button to give kudos if I helped you 
