I just came across an article regarding submitting app to Ubuntu Software Center
http://developer.ubuntu.com/publish/apps/other-forms-of-submitting-apps/commercial-software-faqs/
I'm currently maintaining a open source stock market software. I would say around 80% are Windows users, although the software itself can be executed in Linux too.
I would like to increase adoption of Linux users. Hence, distributing the software in most popular Linux distro will definitely help.
I was wondering, whether a pure Java written software will be accepted in Ubuntu Software Center? It requires JRE6 and above.