Multicolour notification LEDs are a requirement of my idiotically specific phone criteria too, so it doesn't surprise me that much. Not having red for text, green for email, blue for fb and purple for bbm/other instant text service would drive me absolutely nuts. Had it on my Milestone and now my BB and couldn't live without it.
Heh, this is very much what I do with my Milestone. Although a indicator isn't mission critical, it's really amazing to have. The Cyanogen mod I've got has the ability to sequence and merge colours which is also pretty useful. Blue is text. Green is gmail. White is hot mail. Red is missed call/battery low. With a glance, I can tell what I've got. Even my gf recognises the colours now.