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 somewhat terse and heavy going but it seems to support that the TypeBound can only be extends. Sierra-Bates (p627 Cert Guide 6) doesn't explicitly clarify things but the omission of any examples with the form <T super ...> also seems to support this intepretation.