What areas in EE overlap closely with CS
One very close overlap is of course Computer Architecture.

Another close overlap (which incidentally happens to be my speciality) is EDA (CAD for VLSI designers). EDA requires development of fairly sophisticated parallel algorithms for things such as routing, RC extraction, optical proximity correction, etc., as well as understanding of the underlying VLSI physics.

Other subjects include telecommunication and signal processing, as pointed out in Subhayan's comment.