Is a Yahoo developer platform worth the time investment to learn?

Yahoo Introduces Social Developer Platform

"3 elements":

Yahoo Social Platform, a set of REST-based social application programming interfaces (APIs) for utilizing social data related to Profiles, Connections, Updates, Contacts, and Status.

Yahoo Query Language, a new Web service API for accessing other Web services using a SQL-style query language, rather than a lower-level programming code. Yahoo describes it as "a command-line version of Pipes," Yahoo's visual programming system for mashing up and remixing Web data, like RSS feeds.

Yahoo Application Platform, a set of software and services to build applications that run on Yahoo. It includes a browser-based development environment, various APIs and Web services, a distribution and discovery infrastructure, and a runtime and rendering environment.

Yahoo Open Strategy (Y!OS) 1.0 Developer Release announcement and List of Y!OS Documentation.

Is this new hope for Yahoo, or another potential dead-end for an industry laggard?  I remember  Yahoo killing its Facebook wannabe, which, with TechCrunch keeping score, makes Yahoo 0-4 On Social Networking. Yahoo does not equal AOL, but I can't help but think of AOL's shutting down of AOL Journals, Pictures, Hometown, Bluestring, and XDrive.  Is it worth investing the time to figure out something that will potentially be on the chopping block in the future?