At 85 he has not just been an extremely important physicist, but he has been involved with most of the important physics that happened in the 20th century. His recent notoriety is due to his coming out as a global warming denier. Expect some questions about this.
I don't know much about Weil and haven't heard of the others on the lecture series line up. Dyson is a big deal though.
Here's a fairly recent NYTimes story on Dyson.
Here's a link to the ISEPP lecture series homepage.
Lectures are spread through the year and occur downtown at the Schnitzer.
I can get you tickets if you give me some warning.
