Its sad so sad !
Why? What do you think will get better if Bitcointalk would be decentralized? I think it will be terrible if all users have to download all posts by themselves and browse their own local "Bitcointalkchain", meanwhile uploading all posts to other I'd love to see it as an experiment though
Someone could create Electrum-like protocol, server and client so you don't need to download whole blockchain. But it'll be terrible for privacy even if they use VPN/Tor.