This week's book giveaway is in the OO, Patterns, UML and Refactoring forum. We're giving away four copies of Refactoring for Software Design Smells: Managing Technical Debt and have Girish Suryanarayana, Ganesh Samarthyam & Tushar Sharma on-line! See this thread for details.
JME (formerly known as J2ME) has kind of stalled in recent years, and it's not clear that it can regain its momentum. The hot sector of mobile is smartphones, and just about the only hot smartphones that use JME are the BlackBerries.
If you want to use your Java skills, check out Android; otherwise, broaden your horizons and look into iOS (which uses an OO dialect of C called Objective-C).