Contract is required.
Link.
Link2.
Yeah, they're saying a contract is "required" (of course) to use it as a phone.
But since it appears that Apple will sell it unactivated via its own retail stores and online (and use iTunes for self-activation), what remains to be seen is whether the iPhone is essentially a brick until it's "activated", or whether you can use all but the phone functionality.
So no, a contract may in fact not be "required" by any stretch.
And, even if the phone is unusable, it looks almost certain that you'll be able to walk out of any Apple store with iPhone with no contract at all.[1] So the usability angle is really the only thing that's in question.
Also, your first link is an ad that the 2 year contract text has subsequently been REMOVED from, probably because Apple, from a legal perspective, will be selling phones from their own stores WITHOUT a contract. Other news articles saying that a contract is "required" aren't really relevant, because of course it will be required to use it as a phone, and it appears that AT&T corporate stores will make a contract mandatory. But that still doesn't speak to Apple stores and Apple's online store, which will apparently be selling without a contract. So whether the phone is crippled in any way (aside from the phone functionality) before it's "activated" is really all that is unknown yet.
And before anyone says "Oh, Apple and/or AT&T wouldn't let it be sold that way in a million years", consider that 99% of normal humans will get the phone with a contract through AT&T and actually use it like a sane person, and not be clamoring to get it without a contract.
[1] This has been discussed repeatedly elsewhere.