On Mon, 11 Jan 2010, jul wrote:
Known leader of the clean-pipe solution is Prolexic http://www.prolexic.com/Akamai and Verisign also tries to go on this market http://www.akamai.com/security (through CDN) http://www.verisign.com/internet-defense-network/index.html
Indeed, these 3 also ended up on my shortlist after much research. Each has areas they are weaker in than their competitors but they are all worthy.
-Hank