Screaming Penguin - Source Does Matter

Sun has a rundown of what is new in Mustang, AKA Java 2 6.0 or JDK1.6 or J2SDK or what the hell ever. I have to say, the first one on the list is a personal favorite of mine:

Feature: Need way to find free disk space
Bug ID: 4057701
Status: Delivered in b39
Description: Many developers will recognize this requirement from the JDC bug parade. Finally, java.io.File is updated with methods to determine both partition sizes and usage and the amount of free space on each partition.

Check the new JavaDocs

Also on deck for 1.6 are JAX-WS, the new slickified SOAP system, JAX-B 2.0, XML binding that doesn't suck and may actually supplant Castor, JAX-P 1.4 which adds StAX parsing APIs and I hope to god will increase the overall performance too (one of the main reasons .NET does well on SOAP transaction count performance specs is the fact that JAX-P is slow like COW!). Always loved this graph (Crimson being the JAX-P default parser):

And if you are REALLY that kind who likes to read ahead in class, get ready for Java 2.7 or 7.0 or 1.7.WHOPR by checking out JDBC 4.0. Yeah, I don't know where "JDBC 3.0" went either. However, R4 seems to add a bunch of stuff, not the least of which is finally getting rid of that stupid Class.forName() loader invocation. Good god, that should have been gone back in the 1.2 days.