Anyway, this whole discussion is moot.
I couldn't agree more. The bottom line is that most people simply don't want to receive spam, often to the degree that they are willing to pay extra to get rid of it.
I'm sure there is rough consensus in the IETF that getting rid of spam is a good idea. (Maybe a question worthy of a plenary hum to confirm this.)
The only question left is if there are any *technical* components to doing so
(which would be the IETF's preserve), and, if so, what they are.
It surprises me that so many people are so eager to declare defeat before even trying the protocol route. (With current protocols defeat is pretty much inevitable.) If we adopt such an attitude in other areas as well, we would all refuse to have locks on our doors because they don't stop all burglars, and refuse to call the police when someone is assaulted on the street because the perpetrator may have a diplomatic passport.
The problem with spam isn't that legitimate business are legitimately advertising legitimate services. (Although even in those cases I never gave them my email address so even this type of spam isn't completely above board.) For that, filtering or unsubscribing should keep the problem within reasonable bounds. Without forgery it isn't all that simple to bypass filters and legitimate businesses lose more than they gain from trying to do so.
The problem is that we are subjected to all kinds of filth and scams, and the SMTP protocol is severely abused in the process in order to avoid filtering. And this is only going to get worse over time, as people get more adept at avoiding spam. Spammers then simply have to send out more messages and address even more perverse "demand" to make money. Going after them in the real world won't work for the same reason that the war against drugs doesn't work: limiting supply only increases profit for the remaining suppliers so it's more attractive than ever to enter the game. So if we can't get spam under control (which isn't the same as eliminating it) by doing something about supply or demand, we have to do it in the middle by giving users the means to blacklist spammers or whitelist legitimate correspondents and make it sufficiently hard to fake an identity to get around this.
I don't think moving to some kind of SMTPng is quite as impossible as people seem to think. Receiving wouldn't be a problem anyway because the new service would simply fall back to SMTP when delivering messages. Most service providers would be thrilled to switch to a near spam-free email service given the opportunity, so email between service providers wouldn't be the problem. Email between customers and their service providers wouldn't be a problem either: here regular SMTP can be used together with existing authentication mechanisms. So that leaves people running their own mail server: either they have to upgrade, or subscibe to an upgraded email service.
About the "charging for email" thing: this doesn't have to be actual money. Doing it with some kind of cryptographic token that is passed from sender to recipient should work just as well in making sure people can't send many orders of magnitude more email than they receive, and this wouldn't have many of the adverse effects of using money for this.
Mabye a BOF would be in order in Vienna?