1. Live Preview for Themes
Now you can preview your theme without deploying it,Ofcourse this feature was already exist but this version had improved this feature tremendously.for example you can edit Title and Description,change background Image and color and you can also define a new static Home page and see whether the theme fits for your blog or not.
You can also change the Header Image like in below screenshot
2. Twitter Embed
Now you can easily embed your tweets by just pasting the link to your Tweet.
— vivek (@vividvilla) June 2, 2012
3. Enhanced Image Captions
Now you can put the link in Image caption field which will be useful when you are giving the credits to the photographer or website.
For the Above Image I gave link using HTML code