This week's giveaway is in the EJB and other Java EE Technologies forum. We're giving away four copies of EJB 3 in Action and have Debu Panda, Reza Rahman, Ryan Cuprak, and Michael Remijan on-line! See this thread for details.
In terms of software, legacy simple means old. And often times it means no longer supported or maintained. Take a look at this Wikipedia article on Legacy Code which explains in a little more detail. So Legacy Classes means old classes that are likely no longer supported or maintained.