I just read Scipio's mini-rant about Captain Atom and found myself going "Hey yeah! What about that?"
I guess I just assumed that DC had dealt with Captain Atom suddenly becoming evil Monarch in some book I missed. Which would be pretty likely, as Cap hasn't had much profile to speak of in years. Turns out, they haven't. Most recently, Captain Atom went from a middlingly successful exchange student to the WildStorm Universe to a prime mcguffin in DC's Prelude to Countdown to Final Crisis For Serious Really.
So that's disappointing. When I read Countdown: Arena - which I liked, except for the rushed art - I figured that the Monarch/Atom was a dimensional clone or "our" Captain Arom. I suppose that could still be the case.
I was there for Justice League Europe/International and Armageddon 2001. I liked Captain Atom. I liked that all-silver costume with the red burst on the chest. I liked his role as a major figure in the DCU. Not that all of that means much... you tend to like what you like when you first liked it, right?
The thing is, big-power characters always get shafted in DC because everybody needs to come up short when compared to Superman. By definition. Superman screws up the curve. And his marketing drives the company. So guys like Martian Manhunter, Firestorm and Captain Atom keep getting lost in time or cosmically de-powered or psychically shut down or sent to another universe or given ridiculous weaknesses (and, in J'onn's case, given them again after removing them... I'll never forgive DC for that.)
Maybe the problem is, as a Charlton character, Captain Atom just doesn't fit the legacy mold that DC prefers. Wait, scratch that, it's not Charlton that's the issue... DC has had great success with a Blue Beetle legacy, and has even done some tentative work with Judomaster, Peacemaker, and the Question. The real issue is that DC already has two other Atom legacies. Or, at least, one extremely convoluted one that doesn't include Captain Nathaniel Adam.
You've got the original Al Pratt Golden Age Atom, who was a boxer with an Atomic Punch power (who wasn't a boxer in the '40s). Unlike Flash and Green Lantern, there's not much connection to Al's Silver Age successor, the Ray Palmer Atom. Ray was a scientist with the ability to shrink. So Al's legacy first went to his godson Nuklon, who later renamed himself Atom-Smasher (which I always thought was brilliant). Nuklon's deal, aside from carrying off a mohawk way way way after it was fashionable, was similar to Al's... super-strength, plus the ability to grow. But then we find that Al had a son of his own, Damage, who has energy-based powers and now sports a variant of Al's costume. Add to this the new Ryan Choi Atom, who took over Ray's mantle after Ray vanished at the end of Identity Crisis. And with Al dead (thanks Zero Hour!) and Ray missing (only recently returned, but not in costume), Ryan has been the only "Atom" character of note... despite Atom-Smasher and Damage still hanging around.
So how is a "Captain Atom" supposed to fit in all of that? He's not connected to either Atom dynasty; he's just a 1960s relic. "Atoms" aren't even that cool any more. If he lives through Final Crisis, I bet they rename him.
During the character's late 80s-early 90s revival heyday, Cap was pretty much the only atom around. Al was still in Valhalla with the rest of the Golden Agers (ironically released during one of Captain Atom's post-Armageddon jaunts, actually), Nuklon was ignored like the rest of Infinity Inc, Damage and Ryan Choi didn't yet exist, and Ray Palmer was semi-retired. So the name confusion of Captain Atom was no trouble at all. This was when the character was at his best. A powerhouse in the League, a key figure in DC's event storylines.
Since the weirdness of Armageddon 2001, he did a few episodes of Justice League Unlimited. He was pretty central to Kingdom Come (albeit a victim of the common get-the-powerful-guys-out-of-the-story-first ploy). He led Extreme Justice, which sucked. He showed up as a government tool in the first story arc of the Superman/Batman series. Then he split to the aforementioned WildStorm loaner program (with his original, uglyass costume) and apparently made something of himself... only to return to the DCU as a motiveless cypher with unstoppable power. The Wikipedia entry is quite thorough, and even it has little to say about how Captain Atom flipped One Year Later.
I have to hold out hope that DC will explain this somehow during Final Crisis or these last few issues of Countdown. It's just too odd to leave such a major thread dangle like this, even for comics.