You can now generate characters of all 30 levels using the newly updated Character Builder if you’re a D&DI subscriber. Otherwise, you can still download the level 1-3 trial version. I’m still figuring out the details of how many computers I can install it on from the announcement thread on the WotC forums.
The interface hasn’t changed much since I previewed it a few months ago, and I have already found a bug or two when inputting the 4th level version of my Eladrin Wizard/Warlock. Still, I think this will be a big help to the two groups I play with.
(Thanks to Questing GM for the tip).
ADDENDUM: It looks as though the unreleased Bard, Druid, and Invoker classes are there, though I just tried to make a 10th level Druid and was restricted to picking from the first 3 levels of powers. More investigation will have to be done to see how much new material is there.