Patchou...
Since MSN Messenger is a product from Microsoft, it doesn't surprise me that the only "cool" things it has are custom emoticons and display pictures. Honestly, plain MSN Messenger is for computer newbies and the like.
MSN Messenger 7 promises animated emoticons, nudges and winks. In other words, nothing useful for those of us who want/need advanced options.
Messenger Plus! is something else. It's an add-on made for people, and not for potential customers. When I see MP! I don't see a software made to earn money, I see a tool to help people.
I think it's very likely that Messenger Plus! will live for many years more. Nothing that MSN Messenger adds will make users leave MP!
I sure won't stop using MP!
Edit to add: sorry for my poor English