The Roth Rating Report is the best resource to look forward to Challenge Roth and to follow the Pro races on-site or via the Challenge live stream. The Report is a 60+-page PDF with information about the race, its history, the course and all Professional participants with a discussion of their chances on July 1st.
The Report is available for free (just enter 0 in the "Name a fair prize" field you get after clicking "I want this"). However, if you like the report and want to support my work over the year, it would be great if you can send me a few bucks. (For comparison, triathlon magazines sell for about $7.)