This is a great service but with at least two shortcomings:
1) we can’t Retweet other people’s tweets.
2) we can’t Favorites some tweets.

No way?

any tweet has a unique address or maybe a code. can’t you use it to provide possibility of Retweeting and Favorite’ing via IM ?

That would be really great.

That’s right, since there is no reply, forward, or tag in IM.

There is however a reply feature in OneTeam Desktop, that in the context of Tweet.IM uses the right metadata.

Providing the tweet ID in each IM message is obviously the way to got, but it is overkill since it will add a big amount of noise to your timeline…