I am going to be experimenting with ideas in Beta 4, possibly even some client side only team-mate identification stuff (icons over heads, glow color on their weapon, etc.) that can be easily turned off by those not wanting it.
I think that despite some players not struggling to recognise who their opponents are, it is a fact that some do and especially non Bond fans. Some like Valentine and Mishkin are also fairly samey...
I think it would be nice to have some effects to recognise members of your team as a second's hesitation can cost you the gun battle.