Bind [key] say_team "Attack my target".
(Eyes should be able to tel what target your friend is shooting at.)
I would think something like the above is possible in Crysis? I didn't bother to look up the actual commands, but they tend to look something like that.
Yes I agree that being able to see your targets target could be a good feature, but it might not be worth the effort if we can find good ways around it. So I'm just tossing out some ideas how one can "make do" in the mean time.
Semi-related: Ideally I would like to be able to have both a friendly and a hostile targeted at once. Would really help when establishing fire teams. easier to see your "partner" and you can see its health as well, while at the same time be able to have a target of your own selected. Even better would be if when you have a friendly targeted like this his/her target would be highlighted in a minor way and your own primary target highlighted in the current way. Buuut I am probably wishing for a bit much here.
/Merf - Remember the good old times in Quake when team comms where handled by a proxy server transalting triggers like %1 in say_team commands into the players current position on a map, or current health etc.