BIS page: http://www.bis-spaceflight.com/sitesia. ... ge/1964/l/
Tau Zero page: http://www.centauri-dreams.org/?p=6758
From the BIS page:
In the 30 years since this landmark study many scientific advances have been made in areas such as extra solar planet detection, communications, computing, fuels for spaceflight, impact shielding, onboard repair, propulsion and nanotechnology. Crucially, physics advances in both inertial and magnetic fusion technology are also progressing quickly.
The actual Icarus name and specific objectives seem to come from the Tau Zero side, specifically the author of that announcement, Kelvin Long.
The comments on the Tau Zero page are at least aware of Dr. Bussard's work. I don't know if anyone recruited for Icarus is lurking in here...