It’s still in prototype mode at the moment, which means there’s nothing to download just yet. But you can get a good idea of what it’s like from this short video.
There are three primary views: people, conversations, and attachments. The people view groups messages by who sent them, so you can easily see whether you have messages from your mom or your boss. Conversations groups stuff in threaded list, so you can follow a chat between two or people people. And finally attachments view actually shows you the attachments as thumbnails, like an image gallery.
Like the look of it? Think you might be tempted? It will be interesting to see and play around with the full app when it’s released. Best way to stay in touch is probably via the Twitter feed.