I'm not entirely sure what to say but I think he deserves to be remembered here, since his (and fellow co-owner Tom Wright's) store, really got me back into gaming seriously when they opened in 2008. I can't say we were close friends - we didn't hang out or talk much beyond gaming - but we were acquaintances and I'm definitely going to miss seeing him around.
Felix's blog has a nice tribute, as well.
It's not much, but I've made a small donation to the Leukemia & Lymphoma Society in his name. If you'd like to make a donation as well, you can do so here.
Additionally, a collection has been setup at the store to help his family defray medical costs.