Back in Spring last year I posted a render produced with a beta of terragen 2 and mentioned that it had taken around 30 hours to produce. Planetside are now nearly at the release point - folks like me who have pre-paid can download - release is waiting for the website and maybe a few other things. I'm running it using Linux and wine and something has definitely speeded up - maybe the betas had some debugging code, maybe it is better at spotting dual cores (though that fix appeared to go in an earlier beta), I've just repeated that render - well same base file, slightly different camera position and it now takes just over 7 hours! I didn't really notice much of a slow down either.
Four times the speed is certainly appreciated!