Just a week after Twitter added the new local trends feature, they are at it again with a new feature. Twitter just introduced a new feature to some of its users called Hovercards.
Hovercards is a new way of seeing someones profile without actually visiting the profile. In an announcement on the official twitter blog, spokes person Jenna Sampson told how the new feature works:
On any timeline, as its namesake suggests, Hovercards are cards which appear when you hover over a username or avatar. The cards display additional information about the person and allow you to interact with them while staying within the context of your page.
These new Hovercards will come in real handy when you want to find new info on retweeted people and allow you to follow them right there and then. Hovercards also allows for faster sending of direct messages without moving away from the page.
As with the previous feature releases Hovercards isn’t currently active for everyone. Just like all the other releases Twitter Hovercards will be phased in over time to all Twitter users.
If you  are on Twitter you might be interested in my Twitter SMS notification system TweSMS or you can follow me on Twitter.
These are cool, but redundant in the bigger context. Twitter already exposes all user details as an hCard microformat, which means that you have all the details for any compatible site/datastore. The trick is that most “regular” users will not know about that, and this is probably the reason for the introduction of these things.
As microformats become more ubiquitous, we will see less of this type of thing and more interaction of users between more apps.
Yea Twitter stated on their blog that they are introducing this feature because there is still allot of users using Twitter.com to read and write tweets.