Crap. I knew not being a lawyer was going to be a problem here….
But the idea is that the first-sale doctrine will kick in when the laws catch up with the idea that it should apply to digital goods too. Since there’s nothing special about a downloaded game other the lack of a physical medium so the same rights on reselling a legal obtained copy of the work should apply too; but EULA suggest they dont – immovable object versus the unstoppable one.
I’m not sure if the doctrine actually applies in the UK & Ireland other than that reselling physical copies of books, cd’s and games are currently not an issue, hence IANAL, but the expectation is those same rights will start to apply when enough consumers point out the problem.
http://www.mcvuk.com/news/37245/Green-Man-Gaming-offers-trade-ins-on-digital-games is an example proving that transfering the copyright should not be a technical problem.