Yes...to an extent. All things in moderation. SOME reciprocal links is natural. 75% reciprocal links is not natural.
I think you'll be seeing "natural" tossed around as the newest buzzword being repeated infinitely by SEO's in the upcoming months.
'Natural' is being determined algorithmically though...which means there have to be threshholds. Perhaps threshholds based also on other interdependant criteria, but indeed absolute quantitive threshholds. The REAL fun is gonna come as the SE's get better and better at blending their English (semantics) and their Math (algorithms).
Are recip links inherently evil?
Nope. Happends a lot.
Could too man recip links work against your optimization efforts?
Yep. It's all about balance.