Looks like RIM has announced a new developer platform called BlackBerry Mobile Data Systems (MDS) 4.1. It's based on Java and uses Web Services (SOA) on their Enterprise Server to connect applications. MDS is a visual IDE and has application deployment and management built in. Good thing is since it's based on WS it should be able to connect to Windows Mobile based devices as well as Java based devices.
http://www.rim.net/news/press/2005/pr-04_04_2005-01.shtml