While it's not the "rounded rectangle" iPad patent of fame, the iPhone 3G design patent is easily the second most-famous Apple design patent of record. It's called D618677, and it was a key issue in Samsung v. Apple "round one" - and by "key issue," I mean "reason for most of the remaining half billion dollars in damages." According to the USPTO, that iPhone design patent is now invalid on multiple counts of obviousness in light of prior art (in a technical, not literal, sense - two very different things).

Samsung was deemed to infringe this patent by a jury, and while it may well have were the patent valid, the USPTO is saying the point is moot - the patent itself is not eligible for protection.

The main reason behind the USPTO's decision is, sadly, not really one of principle, but more of technical correctness (I doubt Samsung particularly cares either way). The D'677 patent, as it is known in shorthand, relied on two prior patents filed by Apple to obtain its original "priority" date of January 5th, 2007. The D'677 patent itself was not submitted to the USPTO until almost 2 years later, in November 2008. But because Apple claimed in its filing that the D'677 patent was sufficiently described by two other patents it had previously filed, one in early 2007, that it was entitled to the same protection date granted to those earlier patents. Yes, patent law is weird. Yes, this happens all the time. And yes, in certain circumstances this rule does make sense. (Basically, if your first patent gets initially rejected as, say, being overly broad, you can break it up into multiple more specific patents, and those new patents will enjoy the same filing date protection as the original, rejected patent, so long as the new patents contain only inventions that were sufficiently described under the law in the initial application. I know this probably makes very little sense, sorry.)

The USPTO decided that Apple did not sufficiently describe the D'677 patent in those older patents to the extent that it could enjoy their priority date protection, and that means its protection now only extends from the actual filing date of November 2008. The problem is that if you push the protection date that far forward, there is prior art (from Samsung, LG, and even Apple itself) in the record before that November 2008 date that makes the D'677 patent invalid on the basis of obviousness.

Anyway, what's this mean for that remaining half billion dollars or so Samsung owes Apple? Well, it's likely Samsung will get a chance to bring that up in the remanded third trial for the case that is coming up at some point later this or early next year. Either way, it seems very unlikely that Apple will be getting much in the way of damages anymore.