Samsung can go back to court, get the 1bn thrown out and request a licence deal anyway.
Uh, no, they can't. Assume for a moment that the patents in question are judged to be valid. Neither Samsung nor the court can force Apple to license their patents at any price. It is totally up to Apple whether or not to do so. They can license to HTC for $8 and to RIM for for free if they choose, but still refuse to license to Samsung at any price. It is totally 100% up to them.
The reason is because these are not FRAND patents. These are not part of a standard where Apple put them forth in standardization meetings in the same way that 3G, LTE, h.264, and other standards were made. FRAND patent licensing is compulsory. For any other patent it is not.
The reason Samsung wants the HTC agreement made public is so they can get the damages knocked down, so they can tell the court for example that Apple licensed these patents for only $1/phone and we've sold 60 million infringing phones, so the damages should be only $60 million. That gets the damages knocked down, but Apple is under no obligation to license future phones at that or any price, and would still be able to block their sale. The winning strategy for Samsung is to have the patents invalidated or the jury verdict overturned, but they also simultaneously want to get the damages knocked down in case they do not succeed there.
Meantime their software engineers are no doubt working to design around the patents Apple has asserted so they're ready to deploy updated software in case the verdict is upheld. Then if Apple thinks the devices are STILL infringing they'd have to go back to the court and try to prove that to block them. And Samsung could again try to design around them. It is sort of like playing whack a mole, which is why companies usually end up settling and licensing as only rarely does one party get true satisfaction out of this process.
Samsung is also likely interested to know the details of the agreement to gain insight into their competitor, HTC. If HTC licensed Apple's patents cheap Samsung wants to know, and hopefully to learn what HTC might have had on Apple to make them willing to give up a good deal. On the other hand, if HTC's CEO is not being truthful, and HTC is actually paying Apple $18/phone, Samsung would want to know that too, as it tells them they potentially have a huge cost advantage over HTC if they are able get all of Apple's patents knocked down (because HTC would still be paying to license them even if they are later invalidated...that's how most such agreements are written)