i would rather it just marked that message as read. If i am able to click on the notification, then that means i was able to read the tweet. I'd rather not then have to see the message again or have to then open the window just to mark it read.

marking the tweet as read would be fine if it is just text, but if the tweet has a link to a twitpic, video, or html link then bringing the message into focus would let you easily get to the link.

that's a good point, but i think if i wanted to interact with that particular message i could just as easily click the menu bar icon for tweetie instead of clicking the growl notification itself. Especially if you use the auto-scroll to top option, the new message would be right there upon opening the window anyway.

For me at least, it occurs with much more frequency that i want to read a message and then never see it again, then it happens that i want to click on something or reply to it.

Possibly it could even be an option.