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.
The book does not cover migration issues. However, I would recommend identifying those features in the newer versions of Java your application domain could benefit from, learn them, and find out the best way of applying them. While 1.5 is old, it is not as bad as one company I know which is still using Basic. And I don’t mean Visual Basic!