I found out via our mutual friend Tom Watson, who reports that Al's mother posted a comment to the Jon Swift blog sharing the circumstances of his death:
I don't know how else to tell you all who love this blog. I am Jon Swift's Mom and I guess I'm going to OUT him. He was Al Weisel, my beloved son. Al was on his way to his father's funeral in VA when he suffered 2 aortic aneurysms, a leaky aortic valve and an aortic artery dissection from his heart to his pelvis. He had 3 major surgeries within 24 hours and sometime during those surgeries also suffered a severe stroke. We, his 2 sisters, his brother, his partner and his best friend since he was 9 years old were with him as he took his last breath. We have all lost a shining start who warmed our hearts, tormented us and made us laugh as he giggled at our pulling something over on us. He passed away on February 27, 2010. My beloved child will live on in so many hearts. I miss him more than I can say. If you are on Facebook, go to organizations and join "Friends of Al Weisel, Unite!" It will give you just a taste of how special he was. Farewell, Jon (Al)I had emailed Al, Jon as I knew him, a few days before, and hadn't heard back from him, which was a little unusual, but not terribly so. He drifted in and out of blogging, when real life accommodated or got in the way. I was a genuine fan of his writing, and he was an absolutely delightful guy in every conversation I had with him.
I feel really fortunate to have known him and had the opportunity to read the work of someone so devilishly clever and enviably talented. And I feel so, so sad that he's gone.
My heartfelt condolences to his family and friends.