Wow wow wow, wait a minute :P
On my PC it does look like it is Quad Optimised. When I played Vehicle CTF, the cpu loads were like this on average.
Core 1 80%
Core 2 60%
Core 3 40%
Core 4 40%
Which makes a load of 55% and it did spike into 75% at some points. So I think it is QC optimised.

And BTW, this game rocks, best UT ever, so wonderfully fast paced and gorgeous graphics at 1920x1200