TechCrunch reports that Twitter has started linking hashtags. They note that Friendfeed already does this.
Now that they are hyperlinked, when you click on a hashtag, you are led to the search result page for the specific hashtag. Others have been implementing this; FriendFeed (big surprise) has been doing this for awhile. Some of the Twitter clients, including the desktop versions of Tweetie and Seesmic Desktop also provide hyperlinks to hashtags.
Turning the hashtags into links makes good sense and it will increase the usage of hashtags. A couple downsides with hashtags - they shorten the length of a tweet and they are often used by spammers, like they were today with news of Sarah Palin's resignation.
You can see the hashtags turned into links into graphic of a search for the #hashtags hashtag
