Continuing its attempt to get people to tweet through the #newtwitter interface rather than third party clients, Twitter has brought five new content partners on board, enabling users to access more multimedia content without leaving the site.

As part of its September redesign a second pane was added, offering video, image and music content from Flickr, YouTube and iTunes.

Now, the new batch of partnerships will offer web TV shows from blip.tv, quirky photos from Instagram, music from Rdio, presentations from SlideShare and music and arts content from Dipdive, all available to view in the right-hand pane when you click on a tweet containing a multimedia link.

The partnership will be a particular boost for newbies Rdio and DipDive, helping them compete in the crowded social music marketplace. And as the Twitter blog explains, more content partners will be integrated in the coming months.

At the relaunch in September CEO Evan Williams underlined the dominance of the Twitter interface in a tweet saying ‘Twitter.com is the biggest Twitter client. 78% log into Twitter.com on a monthly basis’, before going on to introduce all the new multimedia features which they hope will keep popular desktop/mobile apps like Tweetdeck, Seesmic and Hootsuite at bay.

But to really stop these young upstarts from snapping at their heels, Twitter needs to introduce the ability to tweet from multiple accounts and update other social media platforms through its own interface.

On the To Do list for 2011?