Is Twitter Testing Ads?

UPDATED: It seems Twitter is not testing a new ad format. Details below.

Twitter appears to be experimenting with a range of new features today, including what appears to be third-party sponsored text links on user profile pages.

A box located directly beneath a user's follower numbers is promoting products and services on some accounts, and offers the options to "tweet now" or to "learn more," the latter linking to a third-party site. One ad apparently links to a site related to a movie called "Taking Woodstock."

The changes aren't currently visible from my account (@jackmarshall), but a user I follow, @anjali28, was kind enough to send me the following screen grabs of the changes she noticed this afternoon. Apparently another ad reads, "Thirst In Select Theatres 7/31. A priest becomes a vampire. Tweet if you want to see the movie! Tweet now or learn more."

However, none of the ads mentioned are for brands or products I immediately recognize. We are currently waiting for Twitter itself to verify the nature of the ads, and indeed if the images are even real.

UPDATE: It seems Twitter is not testing new ad formats after all. Rather, it appears the user that pointed this out to me may have forgotten she had installed the ad-supported browser application, Power Twitter.

Before posting, I questioned the nature of the ads with the user herself, who said in an e-mail, "just to clarify, I haven't installed Power Twitter." I've been unable to reach her since to double-check this, and we're still waiting for a response on the matter from Twitter itself.