This is, of course, a very different thing from "The Mistakes Of 'Infinite Crisis'", because I don't know if Blogger has a posting-size limit, and I don't want to find out the hard way.
But for those of you who don't follow comics overmuch, "Infinite Crisis" was a sequel to "Crisis On Infinite Earths", which was designed to do a bunch of harsh, necessary things to DC continuity and then never be mentioned again, ever. Basically, a bunch of the characters from "Crisis On Infinite Earths" who were never supposed to be seen or heard from again because their backstories were too complicated and unwieldy for any but the most hardened DC fanboys to follow turned back up because DC realized, "Hey, that's pretty much all we've got left of our audience!"
And they then proceeded to make a big, universe-altering machine that recreated reality like it was before the original Crisis, because there was so much cool stuff back then, and it was a shame that it was chucked out, and wouldn't it be cool if we brought back the Multiverse, and it's so lame that Batman's parents' killer was never found, and Power Girl really should be the Earth-2 Supergirl, and...and basically, it was the most spectacularly meta-textual story since Grant Morrison's "Animal Man" run. But to make a long story short ("too late!") it ended with the DC history being revised again (third time in twenty years.)
The key thing they did was bring back the Multiverse, which I've likened in the past to having an operation to put someone's appendix back in. Because ultimately, the Multiverse was there as a mechanism to get characters from different DC continuities to team up. When the writer wanted Captain Marvel and Superman to meet, but it was established that there was no Superman in Captain Marvel's world and vice versa, well...Multiverse! All is good. But the original Crisis made the difficult, painful, but ultimately necessary adjustments to DC's history to establish that no, all of these people are in one history, and it had two great waves of super-heroes. There was a Golden Age Flash, and he inspired the Silver Age Flash, and he inspired the Modern Age Flash. No Multiverses needed anymore. (In other words, the new Earth-2 has...all the same heroes as on Earth-1. Only, you know, they're...um, the same age, and...um, there's a new generation of heroes and Robin is now the new Batman, which is totally different from DC now because, um...look, just shut up! Earth-2 was cool when Geoff Johns was twelve, and it's still cool now!)
Which leads us to the great missed opportunity in DC's "Infinite Crisis". Because they're revamping DC's history yet again, right? And meanwhile, over in the Wildstorm universe (which started out as part of Image but was bought by DC, lock stock and every single marketable character), they're rebooting that whole universe from square one (Captain Atom and Void accidentally blew it up. Oops!) So what do they do?
They make the Wildstorm universe Earth-50. So now, if the Teen Titans want to team up with Gen-13, all they need to do is find a convenient dimensional portal to a parallel Earth, see, and then they can meet up and have a several-panel long explanation of the physics of alternate timestreams before they get their adventure started, which will have to involve dimension-crossing villains as well, of course, and...
Why, oh sweet suffering baby Jesus why didn't they just take the opportunity to make the Wildstorm universe part of the DC universe? They own the characters, they're revising both continuities at the exact same freaking time, and if fifty years of pre-Crisis continuity should have taught them anything, it's that having your marketable characters stuck in different fictional universes is a royal pain in the ass that you should correct sooner rather than later, because the longer you let it go on the more irritating it is to fix!
**pants like Animal after a rampage***
But they didn't, and the defining ramification of "Infinite Crisis" remains that it gave us "Countdown: Arena". Which is alone enough to make comics fans everywhere wish it hadn't happened.