We've already heard that both the Xbox One and PlayStation 4 will need substantial patches at launch to unlock their full potential -- or indeed to make them work at all.
Depending on what territory you're in, though, both systems have a few proposed features that won't quite be ready in time for launch. In the case of PlayStation 4, it's the Kinect-style voice commands that you'll have to wait for -- some of them, anyway.
At launch, you won't be able to wake up the PlayStation 4 using a voice command, nor tell a video to pause; you will, however, be able to turn the system off and launch games. Third-party apps will not support voice commands initially, but Sony hopes each of the app makers will add such functionality in future.
Voice and gesture commands are relatively low on Sony's list of priorities at present, since the PlayStation 4 doesn't come bundled with the PlayStation Camera by default; every Xbox One, meanwhile, comes with a Kinect in the box and is thus ready for you to shout and wave your arms around to your heart's content. The PlayStation 4 does, however, come with a mono headset which can be used for both chat in online games and taking advantage of those voice commands that are supported at launch. It can presumably also be used to narrate gameplay footage streamed to Twitch or Ustream through the PlayStation OS, but you'll need a PlayStation Camera if you want to share your beautiful visage with your adoring public as well as your voice.
We're getting a good picture of what PlayStation 4 itself can and can't do at launch, then, but what about the people with the controller in their hands -- what are we allowed (or not allowed) to do?
In preparation for PlayStation 4's launch, Sony changed its terms of service for PSN's parent network Sony Entertainment Network this month, and for once, people actually apparently read them all the way through. Of particular concern to some was clause 7 of the software usage terms: "You must not resell either disc-based software or software downloads unless expressly authorized by us and, if the publisher is another company, additionally by the publisher."
The phrasing of this clause was read by some to be completely contrary to what some refer to as "the moment Sony won E3 2013" -- the announcement that PlayStation 4 would not be imposing restrictions on used games or sharing discs with friends. However, Sony confirmed to our sister site Eurogamer that "consumers will be able to sell or share their PS4 disc products." Sony Worldwide Studios boss Shuhei Yoshida also confirmed the news on Twitter.
Thankfully, this means that this endearingly cheeky video is still accurate:
Clauses such as these have been in software license agreements since time immemorial: for example, I have a floppy disk-based copy of 1992 PC game Wizardry VII on my shelf right behind me in which the back page of the manual explicitly states that "the distribution and sale of this product are intended for the personal use of the original purchaser only, and for use only on the computer system(s) specified herein," suggesting that technically I'm not allowed to 1) give, sell or trade the game to someone else or 2) install it on computers other than those specifically stated on the packaging -- but in practice, there's no real way that either of those terms can be enforced. The terms in Sony's new agreements, while phrased differently, are much the same -- in fact, in many ways they're less restrictive, given the "unless expressly authorized by us" phrase.
Essentially, the "new" terms are a variation in the end-user license agreements we've been agreeing to without reading for years now: you're purchasing a license to use the software rather than the software itself. Although the terms appear to explicitly forbid resale or trading of games, Sony's public reiteration of the fact that you will be able to sell or share disc-based PS4 titles can be taken as the "authorization" necessary to effectively void the statement insofar as physical products are concerned. As for digital products, there's still no real means of selling or trading those anyway.
In other words, don't worry; when you tire of your PS4 games, you'll still be able to trade them in for new ones or sell them, just like you've always been able to.