In a bittersweet note, forummer DiveTwin reports this note that appeared in Cinematical:
Lee isn’t interested in filming in New Zealand again because it is simply too far away, for too long of a time. You can hear the tiredness in his voice — and perhaps a bit of regret too.
That doesn’t mean Lee isn’t interested in being in The Hobbit at all, however! He’ll appear in the film as long as he can stay in London, and there’s a character he’s quite keen to play. Or rather, voice.
Cinematical gives a link to the original Rushprint.no video interview in which Mr. Lee talks about Return of the King, Saruman not appearing in The Hobbit, him not returning to New Zealand and his offer to voice Smaug. [Cinematical] [Rushprint.no]