There are some wonderful remembrances posted on his facebook page, and lots of links to performances. Mudcat's own Dan Schatz posted on December 6 at 6pm:

My heart is broken to learn that our dear friend Jon Pickow passed away this morning. It was leukemia in the end - but I know he was comfortable and without pain, and there is a blessing in that.
Here we all are in happier times - playing at Caffe Lena with Susie Glaze and Kenny Kosek.

I'll be singing one for you, Jon. More than one.