For the 25%: wouldn't they just decompile the current version?
I'd be more than happy to help de-spaghetti the code if it was available.
Plan for now is to release it under the GPL version 2 or 3 to hopefully compel people to make their modifications available (plus there's not much use for a lenient license here -- it's not a library, though some of the code could be moved to one later). This might take a day or so, so I expect this post to disappear into complete obscurity before I'm done. Might create a new HN submission for that just to let people know. At any rate, my net access is down so I have to write this on my phone, meaning any release is going to wait on my ISP to determine what's up and how to resolve the issue.
So, open source is planned, I'll just suck it up as I usually do when I release every other project of mine. Re: malware, I've decided it's not my responsibility to protect people from the malicious few. I'll let Google do that.
but I understand the 25% bit. It's a shame the android market is so hostile.