OK, I know I've speculated about this before, but I now know from an inside source that Terry Serepisos' team has had a pre-application meeting with the council for an apartment building on Lambton Quay. This would indeed be Wellington's tallest building, but only if you include the mast that is part of the design.
I haven't seen any plans, but apparently it looks pretty good: much better than some had feared. It is indeed supposed to go just north of Cable Car Lane, and while it's hard to see where on earth you could fit in a skyscraper there, apparently there's some space tucked in behind Hallensteins House. That would make it a very narrow building, but of course that would just add to the slenderness and daring of the design.
I think I'm starting to get a bit excited about this!