Due to launch late next month, the PS4 is a dramatic shift from Sony's previous consoles. Based, as with Microsoft's rival Xbox One , on a semi-custom eight-core AMD accelerated processing unit, the device is the company's most PC-like console yet - right down to the use of a BSD-based operating system.While the new architecture brings with it considerable performance gains over its predecessor - at least one game developer has confirmed that its flagship title will be running at 1080p/60 on the console - Sony is also sacrificing some much-loved functionality, and seemingly doing so in the name of profit.In what Sony describes as The Ultimate FAQ , the company has unveiled some previously unknown facts regarding the upcoming console. While many relate to shiny new features like the revamped graphical user interface - known, apparently, as the PlayStation Dynamic Menu - and the ability to have 2,000 PlayStation Network friends, others reveal missing functionality that could give some cause to reconsider their purchase decision.Chief among these is the removal of media playback support in the PS4. Unlike the PS3, Sony explains, the PS4 will not be able to act as a client device for Digital Living Network Alliance (DLNA) streaming, play MP3 files from any storage device, or even play back audio CDs. For those who use their existing PS3s for more than just playing games, this news will likely come as a blow - and is near-inexplicable, given that Sony was the founding member of the DLNA.The reason becomes clear when you read the company's FAQ, however. Asked whether the PS4 will support playing a user's own background music during gameplay - a standard feature of the Xbox 360, and a feature supported by a large number of PS3 games - the company's reply is thus: 'In other words: yes, you can listen to music during gameplay, just as you do for free on the PS3, but only if you cough up a minimum of £4.99 a month for Music Unlimited's Access Plan or £9.99 a month for the cross-platform Premium Plan. Likewise, if you fancy watching a film on your PS4 you can't stream it from your DLNA-compatible home server as you did with your PS3 - but you can pay to stream it from Sony's Video Unlimited instead.Other features, too, appear to be moving the PS4 into far more of a limited, locked-down system than the PS3: the FAQ listing confirms that the PS4 has no support for external hard drives, something the PS3 supports just fine.While Sony has yet to make a formal statement following the uproar caused by the release of the FAQ, its executives have taken to social networking services to quell unrest. None have stated an intention to change the status quo, however, but merely indicated they will '' to the developers - opening the possibility that the functionality may be re-inserted some time after launch. For now, though, those who use the multimedia features of their PS3 heavily would do well to reconsider an upgrade to the PS4.