Been playing around with Windows Live Messenger, the latest version of MSN Messenger.
Like all good things these days, you need to be invited to play. It's also only in beta at the moment.
Despite looking prettier than previous versions, the main difference initially seemed it was now much harder to tell who was who if your contacts change their names on an hourly basis.
But there is a great new feature: offline messages. You can now send messages to contacts that are offline, and they'll receive them next time they sign in. This works for people running older versions of Messenger, too – although they only seemed to show up with people running MSN Messenger 7.5, so it doesn't look like you're guaranteed the person will receive them at the moment. But it is still beta.
Windows Live Messenger and all its pretty colours