I'm more used to draft than sealed, so even with a guildpak I felt like my card pool for the event itself was bad. Despite this, I took 3rd place with Izzet and came into possession of a truly ridiculous number of boosters.
From last Saturday, I learned that Izzet are insane because Hypersonic Dragon is an absolutely brutal finisher and almost every rare is useful for them (unlike the others, where there are terrible rares - I opened Azor's Elocutors from my Azorius pack.)
I can't tell if he will be a bomb in Standard, though. There's no question that he's powerful - a 6/6 flying trampler with a "drawback" that might as well not exist for these colors and an added effect that, while not likely to be important, certainly doesn't hurt. On the other hand, he has no defense against removal and little effect on the board the turn he drops.
Actually, I take that back. Many artifact creatures would be free the turn he drops. I wonder if there are enough playable ones for that to matter. Probably not, and with the Titans rotating I doubt there's anything more expensive than Rakdos himself worth running in a Red-Black aggro deck. In Modern, however, he's kind of intriguing. I'm curious if there's a deck to build around Rakdos accelerating out Darksteel Colossus or Eldrazi.
In Standard, though, his added effect is shrug-worthy, it's his body and fighting abilities that are notable. Right now the format is defined by midrange creatures, which puts some hurt on a RB weenie rush strategy. Rakdos gives the gonzo-aggro deck a control-style fat finisher who wins fights against midrange creatures, at a mana cost an aggro deck can support.
Rakdos, in standard right now, is still going to be incredibly powerful. It does take the right kind of deck, but there's so little removal that hits him so he'll always have a board presence. (Ultimate Price, Tribute to Hunger, Tragic Slip, Dreadbore and Abrupt Decay are the big pieces of removal at the moment, and only one of those consistently hits him.)
That said, yes, he is clearly much weaker because the power level of artifact creatures has plummeted with Mirrodin's rotation out, and RB is basically going to be "Lots of Haste and Unleash" - still, with that deck, you're going to be getting the damage through regardless, and at that point, Rakdos is a 6/6 Flying Trampler for 4. The lower cost thing doesn't matter, because that is pure cost-effectiveness and can tear through an opponent without the answers (and, as I said earlier, there aren't a huge number of answers right now.)
This is why I am currently building UW Control. The only things that are killing my deck at this stage are Tribute to Hunger and Bonfire of the Damned, so 4 Witchbane Orb in the sideboard means I have no trouble beating pretty much everything in my local meta. Woo!