Megiddo, I could possibly see this being used in 'spectate' to tell what actual tool is being used by the spectated player.
Currently, spectate only shows what the "Spectator" "gmod_toolmode" is when the "spectatee" changes to the gmod_tool weapon.
I've not looked to see how difficult it would be to update the spectate code, but perhaps when the gmod_tool weapon is chosen on the spectatee side, update the spectator's gmod_toolmode.
Again, I've not looked at the code. Might be more difficult than it sounds.
If possible though, I feel it would be of great benefit to know what players are doing/using more quickly than waiting and hoping whatever tool they're using shows itself off (duplicator, etc)