Something like that. Apparently regular sexual intercourse is painful for cyborgs since they have enhanced feeling or something, so most of em do the lesbian thing. You see traces of it in the SAC series with Makoto dating a nurse and being involved in an implied threesome at some point. In the manga there is a scene (or a whole chapter, I forget the details) where she has a boyfriend.
What that comes down to is manga version: Bisexual, movie version: un-known, SAC: lesbian
EDIT:
...And hot and bisexual again in the Ghost in the Shell: Stand Alone Complex-verse.
I'd argue that shes at her hottest in SAC. Another area where it beats out the others