I think the deadline for 2010 submissions has passed. Is seems there wasn't much interest, but in any case I guess they have these every year so if you are interested you could shoot to submit something next year.
what have you submitted (if it is permitted to ask?)
Actually ... nothing.
I just heard about it before I posted it here. I didn't have time to prepare anything for the deadline. I'm also not sure I'd submit anything, but maybe some phonics workbooks I've put together.
You can't submit anything that has been published and I didn't read about submitting things that have been posted to the web. In all reality, they are looking for things to publish. It's a win for them and win for you, as you get paid royalties. If the materials have been made available on the Net, they may not be interested ...