IDs would be nice. It helps when I'm having a back and forth conversation with somebody to tell if I'm still conversing with the same person, because sometimes you have cases where your topic introduces new people.
I know under an ID system you're still anonymous and the same ID doesn't follow you from thread to thread (I believe it's based on a formula based on a combination of IP address, browser cookies, time of thread creation, and one other variable that I can't think of right now); and also when you use sage, the ID is "disabled" and says the word "heaven", so if you don't want your ID to be shown you can just use the sage function.