It could replace msn messenger because the purpose of both is same but Skype is more advanced model of chatting. More for video chatting. Tony Bates blog lines goes as:
I’m excited to announce that Skype and Microsoft have entered into a definitive agreement whereby Microsoft will acquire Skype for $8.5 billion US. Once the acquisition closes, Skype will become a new business division of Microsoft. It is an exciting day for all of us at Skype – we’ve taken a significant step towards realising our vision of making the world a better, more connected place.It is very good money and also very good platform for chatting. Mr. Bates said it is the last post he had made as ceo of this sold company and will be writing as the head of Microsoft Skype. But will it be named as Microsoft Skype as other application or it will simply goes Skype? It is soon to see.
And Microsoft could be supporting the login of Microsoft’s chats over this messenger.
Take a look at this post.