The Last Guardian, a game first teased by Team Ico in 2008 that has since been notoriously absent during subsequent conventions, productions and shows. The last we heard of The Last Guardian was when it didn't make an appearance at E3 this year. During the show, SCEA's Scott Rhode told us, "It just wasn't appropriate for us to give an update. That's just how it worked out."
The trademark was abandoned "because no Statement of Use or Extension Request [was] timely filed after Notice of Allowance was issued," the USPTO TARR report states. Sony may have unintentionally let the trademark lapse, and has two months to file a petition to retrieve the application, according to its notice of abandonment.
The Last Guardian trademark was issued in January 2010, meaning Sony has until January 2013 to prove "use in commerce" and retain the mark, according to sleuth superannuation. "Use in commerce" would mean a completed, marketable game, which doesn't exist, as far as we know. Sony can of course register The Last Guardian in a new trademark if this one lapses.
Regardless of whether Sony intentionally abandoned the trademark, accidentally letting it lapse would seem to indicate a lack of focus on The Last Guardian, substantiated by the lack of content shown to the public.