FYI I had been searching for something like this as well and I spent some time with DOTTIMER and it has a "Notification" mod component that can find ANYTHING in the combat log. It can notify you of buff gains, buff losses on yourself, your party, enemies ANYONE.

It is very customizable and you can configure it to output to any chat channel, your combat log, middle of the screen, raid warning etc.

Now my mage can finally use Hot Streak! WOOT! I have my tank setup to watch for my mage gaining the "Hot Streak" buff and it displays an alert on my tank's screen (he's my main).

WAY COOL!

EDIT: In fact it can notify you on ANYTHING in a chat channel, ie spammers, your friend psting you, a motd change, whatever you want!