Will the Twitter Redesign Threaten Tumblr?

Unless you’ve been living in a bird-free zone, you know that Twitter recently overhauled their home page.  The new page allows people to see shared videos, links and photos directly within the stream of Twitter by clicking the ‘open’ button.  Photos are expanded, videos are displayed and even links to text articles are expanded into small snippets of the original source.  I worry that this is going to take its toll and put pressure on services like Tumblr.