Article is a tad biased. Galactus and Darkseid have battled to a draw, and only because Darkseid couldn't harm Galactus and Galactus was unable to feed off of Apokolips, hence making the battle meaningless.
Darkseid gives Superman fits, so the chance of CK being able to deal with the Devourer of Worlds.. Not that high, heck, the Green Lantern and the Silver Surfer have fought to a standstill as well and the GLs have proven to be a tough foe for Superman to beat as well, so the chance of CK being immune to the Power Cosmic.. Not that high.
Jedi? Depends on the Jedi in question: Jollee Bindo, Jacen Solo and Kyle Katarn are more Unifying Force oriented, the Force is neither Light or Dark, it just is, and dependant upon how the wielder uses it, is whether it could be considered dark or not. Luke Skywalker has fallen to the Dark Side in the past, as well, so he does have access to such powers, though he chooses not to use them, due to his own "fear" of corruption.
Anyway, that effectively means that the initial three Jedi I mentioned could use powers against the big S. which could be considered Dark and which would definitely hurt him. Plague, Lightning, Affliction, Choke, Slow, Insanity, Horror etc. And that doesn't even include the age old: We're not the Jedi you are looking for trick. That chap with the bat emblem on his chest is one though.
