Eclipse Ganymede has been out for about two weeks now, but when perusing its download page I didn't find links to the New and Noteworthy items in each package. The Java EE package would appear to be a hit, likely because that's an easy way to install the Web Tools Platform. Admittedly I'm biased since I both work on WTP and regularly coordinate its New and Noteworthy documents, but check out what's new in WTP right here. As if that weren't enough, to really see all that's new in the "Eclipse IDE for Java EE Developers", you also want to read about what's new in the Data Tools Platform, the DSDP's Remote System Explorer, EMF, Mylyn, GEF, and the Eclipse Platform with its JDT and PDE trimmings.
You might want to go grab a drink before you sit down and read it all.