Interestingly, like many current well-known greats in poker, I knew Viffer in more humble days on Pokerstars.
At the time, he was not a high stakes player, and in fact was best known for going to the Pokerstars 100-200 game, sitting down, and immediately sitting out.
During the WSOP event I won in 2005, I met Viffer in person for the first time. He wasn't playing, but he approached the table, jokingly sat in an empty seat, and asked me, "Can I sit out here?"
So Viffer was once better known for sitting out in high stakes games than actually playing them, which contrasts greatly with the risk-crazy nosebleed player he eventually became.
Other stories of mine from the Pokerstars past include Grinder being one of the bigger fish of the 30-60 limit, as well as a then-unknown durrrr approaching me at a karaoke place and telling me he was honored to "finally meet Dan Druff".
Never would have guessed that any of these people would become what they eventually did in poker.
There is some speculation that Viffer is quitting because he's broke. I doubt that -- or at least that couldn't be the only reason -- because I'm sure he could find people to stake him.
I also have to give Viffer credit for being the one to aggressively push the situation of the Stoxtrader collusion scandal on 2+2, when the site originally sought to cover it up. Viffer's involvement (which he did simply because he felt it was right) was what changed it into a scandal too big to ignore.