With Outlook.com, you know that's more modern. One thing that I noticed today is that when you click on a folder, the read pane place holder message and the messages actually slide in from the right. I didn't actually take video of this, but it's a nice visual CSS3 transition.
I also noticed that when you click the "Empty" button for the delete and junk folders, the message popup with the confirm button slides down from the top of the screen, a new CSS transition that must have been added with this very recent update.
For now, this is all that I'm noticing that's new. Of course on Hotmail the interface is actually ligher, but it does not have the UI updates that Outlook gets. It's a low trade off for solid custom branding that I have set up, anyways.
One thing I did want to mention that I like about Outlook.com is when you send a message. When you click send, you have the normal CSS3 powered loader next to the now "Sending..." text, but when the message is sent the message sort of shoots to the back of the inbox, then exits while shooting up, as if you really were sending a message. Transitions like that add nice eye candy and I actually email a bit more because I like seeing the effects.
