The Afline weighs 1590g, 50 more than the nexus. The site quotes the Alfine as having the "highest shimano internal hub efficiency" and has "double roller clutch for smoother, quieter shifting".
Hmmm... If Shimano is phasing out the nexus 8, methinks I should weight till prices fall. What do you think?
About purchasing the Afline, I've come across posters in the touring/cyclocross forum who have their bikes draped in Alfine, and with pics too.