I'm a member of this club too, and have tested a lot of shoes for Backpacking Light. For truly wide shoes, go to New Balance. I personally like the 872 Off Road for lightweight, support, and breathability. They are available in 4E and I get them in my normal size, which is 11.5

That said, there are also some other really good wide shoes out there. My very favorite shoe right now is the Vasque Velocity in the wide width (med, narrow, and GTX also available). The Velocity is quite light and really durable and supportive. Its especially good for off-trail hiking. I get them 1/2 size larger than my normal size.

I also like the Keen Wasatch Crest. They are very comfortable and supportive, and so far their eVENT lining is waterproof (the current model uses KeenDry I believe). I also get these 1/2 size larger.

I also like the GoLite shoes. They run quite wide and have inserts to adjust the volume.

Another good wide shoe is the Montrail Hardrock Wide. Again I get them 1/2 size larger. This shoe is very durable and supportive for off-trail hiking.

Another good wide shoe is the Kayland Dragonfly. I get it 1/2 size larger, and it has an eVENT lining that leaks.