There was alot of of talk/flames on the LKML about devtmpfs. Looks like a big push for this was for embedded devices, android, etc. Since I read that it may give a boot time speed up, I was slightly intrigued. http://lkml.org/lkml/2009/4/30/182, yes…it is an old topic but it finally was released in stable .32 kernel.
So, where is the real win here? Well, as I wrote before, use openrc.