Well that was fast. Samsung announced late last night that it's countersuing Apple, and it's taking the fight international -- there are lawsuits in Korea, Japan, and Germany, alleging that Apple's infringing a total of 10 patents between them. Samsung didn't announce details of the cases, and I don't have easy access to filings in those countries, but Reuters says the patents involve "power reduction during data transmission, 3G technology for reducing errors during data transmission, and wireless data communication technology," which is vague enough to mean almost anything in this context. Samsung is a major international patent holder, so it's not surprising to see them up the stakes -- and the cost -- of litigation here, but I doubt this will faze Apple into doing anything other than countersuing in each of those countries.
In fact, you might just characterize these suits as simply being additional theaters of conflict, designed to influence the main skirmish here in the US -- if Apple and Samsung decide to settle their US lawsuit I'd wager the rest of these settle immediately as well. Conversely, if Apple or Samsung pulls ahead in one of these foreign countries, the pressure to settle the US case and avoid a potentially damaging precedent abroad will increase dramatically. It's a risky move, but as I've said before, this is multibillion-dollar chess, and there's no escaping some calculated risk.
The real action will come when Samsung files its reply and almost-inevitable countersuit here in the US. That's when we'll hear Samsung's side of the story, including its response to Apple's specific claims, and get a better idea of how the company intends to defend itself. The reply isn't legally required to be super-detailed, but I think Samsung realizes it's being judged in the court of public opinion as much as anything else, and I expect their attorneys to paint a compelling counterargument. I'm guessing we'll see that within a month or two, so stay tuned.