We have lots of plans for adding onto Jazz. After that, we'll start looking at performance, zooming widgets, support for large images, amonth other things. We also plan on replacing the current file format with an XML-based file format, as well as adding serialization. This list is restricted for the Jazz team to send out occasional new version announcements. There is a registration form on the Jazz web pages where you can add yourself to the various mailing lists.
Jazz is completely open source.
You can download and use Jazz however you like. The only restriction is that you must continue to make all modifications to Jazz available to others, according to the Mozilla Public License. Note that you are not obligated to make your applications open source. You are free to protect your applications in any way you see fit - although of course we encourage you to make them open source as well. Yes it is.