We're glad you asked that question...we'd like to make it easy for people to continue to use and expand on the existing Titanium Studio desktop integration.
As such, we've open-sourced it here:
And you can download a pre-built version of the latest plugin here:
We're currently running that build as part of our nightly build process, so it should help keep it from getting out of sync if we happen to refactor the core code base.
While we won't be able to add new features ourselves, we're happy to help get other contributors started with the code base.