I published some Free rebuilds of the Android SDK, NDK and ADT at:
http://android-rebuilds.beuc.net/
As described in my previous post, Google is click-wrapping all developer binaries (including preview versions for which source code isn't published yet) with a non-free EULA, notably an anti-fork clause.
There's been some discussion on where to host this project at the android@lists.fsfe.org campaign list.
Build instructions are provided, so feel free to check if the builds are reproducible, and contribute instructions for more tools!
Following the discussions, Replicant is currently thinking about earlier, SDK-focused ports, and F-Droid expressed interest in freeing the SDK&NDK they use (although the diversity of the packages means all SDK platform versions need to be available).
I think it's important to keep rebuilding and testing the dev tools, to assess feasibility and raise confidence.