We’ve also brought the reblog button back to the toolbar that appears at the top of the screen when you’re logged into WordPress.com. Note that you’ll only see the like and reblog options while you’re looking at individual posts.
For example, you’ll see this on the left side of your toolbar while viewing http://en.blog.wordpress.com/2012/01/20/read-blogs:
And your toolbar will look like this while you’re browsing the home page of en.blog.wordpress.com:
What happens if I reblog a reblog?
If, for example, Stephane reblogs a WordPress.com announcement on his site and Lori reblogs Stephane’s reblog, Lori only re-publishes any comments Stephane made about the announcement. If Lori wants to share the original announcement, she should reblog the post from en.blog.wordpress.com, not from Stephane’s reblog. But if Stephane leaves a really clever comment, Lori might want to share it by reblogging his reblog on her site.
Can I edit a post I’ve reblogged?
You can go back and edit the comments you left when you reblogged a post, but you cannot edit any parts of the original post excerpt (including the post title). If you like, you can add categories or tags to the post. Reblogs show up underPosts → All Posts in your dashboard, and they can be edited the same way you edit your own posts.