Now, I'm not a developer, I think you've probably guessed from all the writing I do here and it's a well known fact that develops don't write creatively all that well. This isn't to say I've not dabbled in the SDK side of the Android pool in fact, I have the SDK set up and installed on my Ubuntu machine and tried to write an app at one point but, it didn't work out all that well, at all. So, I think what I'm getting at here is that it's best to leaves these sorts of things to those that know what they're doing.
Which is exactly what Google are doing with Jelly Bean as of right now, each and every time an Android release gets announced and detailed the SDK follows suit like a prompt butler. It's always there and that's a fantastic thing for developers large and small alike. Having such access to a development kit before even the Nexus line gets the update gives you a head start on the game and I respect Google for treating developers properly when it comes to their development tools.
To this end, Google have released the Android SDK Tools Revision 20 alongside ADT20 as well, that's right, there right there ready for you to download. The new revision of the SDK Tools brings with it a number of enhancements and fixes, as always and includes a stand out feature by the name of "System Trace" or systrace, for short. This is something that has come along for the ride with Project Butter and allows developers to track down graphical errors and the like that might slow down the app or not make it run so...buttery.
If you're an Eclipse user then the Android Developer Tools have been updated to match the new revision as well and these are also, available now.
As always, there's a myriad of new information to be found at the official Android Developers website here.