It would be very beneficial to have the Web Inspector denote which domains requested in the loaded document have been identified as a "tracker." This will increase transparency and improve debugging ability for Web Developers.
We've received similar requests from others, and are working on some tools in the near-term to provide basic ITP debugging support. See the FAQ at the end of the blog post: https://webkit.org/blog/8311/intelligent-tracking-prevention-2-0/