I can't read the cracked article right now, the company firewall has blocked the site for the reason: "The category for this site is Tasteless." First time I have run into that particular reason for blocking a site.
Anyway, without having read the article, Superman is not quite as unbeatable as many seem to believe. He does have the kryptonite weakness that is exploited over and over again, but that has not been the only way the Superman problem has been solved. He gets his power from the yellow sun and loses it when faced with a red sun (I'm not sure how he fares when in proximity to blue or white suns), leaving aside how ridiculous that may seem, he was made powerless toward the end of the Action Comics Vol. 1 run, when he went to a future Earth where the sun had been turned red. More recently, he tangled with an ultra powerful virus infested Doomsday. After defeating Doomsday, he was infected with the virus himself, and became Superdoom, an evil and more powerful version of himself.
If Superman can become more powerful, and has easily exploitable weaknesses, then he isn't the ultimate unbeatable superhero that some make him out to be.
With regard to Supergirl, we will have to see how they approach her in the upcoming series. I personally liked Kara Zor-El best as a Red Lantern, but I doubt they will go there.
