Kurt Mehlhorn will receive EATCS award! Read about it here.
He has had a LONG and PRODUCTIVE career with many EXCELLENT papers.
While he is mostly known for
data structures and algorithms and Comp Geom, he did do some
complexity theory early on.
is a list of his papers up to 2007. Note that the first few are
in complexity theory.
People in TCS can change fields easier than math since there is less
background to learn. At least that was true at one time.
I think it is harder to switch fields in Comp Sci now then it was then
since now we know more.