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.
It is just an opinion of course, but it will be a while before JEE7 will really be used by corporations. There is also little study material/mock exams available for the not yet existing exam. I think it is a better idea to go for the 6. If you should find you need the 7 after all, you can always do the upgrade exam in the future.