According to Sony, the new SKU has been released in response to the finalization of the AACS standard. AACS is the content protection system that governs Blu-ray Disc. The finalized standard limits analog output resolution as follows: All new players sold after December 31, 2010 "must limit analog video output of BD content to interlaced standard definition (480i/576i). Then, 2013 is the expiration date for analog video: no player that passes "Decrypted AACS Content" to analog video outputs may be manufactured or sold after December 31, 2013," says Blu-ray.com."
Blu-ray, therefore, will become the first video standard to decisively close the 'analog hole' and prohibit analog output, period. The existing AACS standard allows companies to release content that can only be played back on HDCP-supported digital players immediately, but notes that use of the restriction is expected to be limited--at least, for the time being. If there's an upside, it's that Mandatory Managed Copy also made it into the final definition. MMC states that consumers must be able to make a copy of the disc for use in a home theater system or a digital player. Use of said copy can still be restricted, but its existence is mandatory.
Sony, meanwhile, is going out of its way to stress that this new SKU brings the PS3 into AACS compliance without impacting the function of other PS3 systems. There will be no firmware update to remove the ability of previous-generation PS3 consoles to display Blu-ray via component out, and Blu-ray output will be the only thing affected. The new "K"-series console will still be capable of displaying games, streaming content, and downloaded material at HD levels.
The problem here is that there are plenty of HDTVs in service and on the market with a limited number of HDMI ports. The standard has been widely adopted across a range of home electronics, such that there's quite a bit of competition for what, on some displays, is just a single jack. Owners of such displays are in no immediate trouble, but may have to watch future purchases carefully--and run the risk of ending up with an incompatible PS3 in the event they require warranty service.
More generally, this continues Sony's years-long trend of removing features that the PlayStation 3 once offered as standard. The current high-end model offers more than 5x the storage of the original PS3, but just half the USB ports, no OtherOS support, no backwards compatibility, no flash reader, and now, no component out support for Blu-ray playback. Sony has justified all of these changes at one point or another, but they remain the only company whose current generation hardware offers fewer options than five year-old models.