If a traditional encyclopedia wanted to attack Wikipedia--and I don't think you need to be paranoid to assume such a wish--they don't need to win, but only to bankrupt the entity they're suing. Their case doesn't need to be good enough to win. It only needs to be good enough that court couldn't refuse to consider it.
That's not all that's needed. There also needs to be a threat that the lawsuit could bankrupt Wikimedia in the first place. Over a list of titles I just don't see it, even if we just gave up on the merits, which are in our favor as well.
Even then there is relatively little incentive for a traditional encyclopedia to attack Wikipedia in the first place. So they bankrupt Wikimedia? That's just going to make Wikipedia grow even bigger. Fine, the legal entity of Wikimedia would be bankrupt, but Wikipedia is much more than a legal entity and it will survive with or without Wikimedia. Besides, the support would come pouring in from all over the place. We'd probably get plenty of legal support donated to us. Maybe this wouldn't be the case if we blatantly flaunted the law (although it still might be), but in a case like this where we're actually in the right, the support would be tremendous.
The only reason we should even consider backing down on this is if there's a serious legal argument that keeping this list would somehow taint the rest of the encyclopedia. I highly doubt this is true, but I'm not a lawyer, and if a lawyer says this is plausible it's something we should look at hard.
But otherwise, if it's just a list, I don't see the problem. The worst reasonable case scenario is that we have to take it down. A long drawn out legal battle; a chance to set a precedent that can be used in the future; that'd probably be a good thing.
Anthony