SifJar said:
Even if there were another exploit, it'd be a very stupid move to release it now. There are already two easily patchable exploits, and one not so easily patched (most unlikely unpatchable, but that is not related to this topic). If there were another released, Nintendo would just patch it too with the next update. Would make far more sense to keep it until the next update which will inevitably block Indiana Pwns and the Yu-Gi-Oh exploit (both can be patched in the same way as Twilight Hack, so they just need to add a couple of title IDs to a list).
Both games are not produced anymore and not availabe in many places. There are a few resellers, but they want 100 - 200 Euros for one of the games, really.
By the way, there is a rumor of a new version of Yu-Gi-Oh Wheelie Breakers with a fixed exploit around, which was produced in 2010.