Last year also had the walking dead, but also journey, amalur, asura's wrath, Devil Survivor 2, Mass Effect 3(and I mention this as an anti ending guy), graces f, xenoblade chronicles, Fez, Gravity Rush, spec ops: the line, Guild Wars 2, FTL, Tokyo Jungle, Unfinished Swan, Hotline Miami, ZE: Virtue's last Reward, Scribblenauts Unlimited, Borderlands 2, Far Cry 3, etc etc.
2012 was pretty solid in my opinion. If it seemed disappointing it probably comes from a lot of really really big titles arguably ending not delivering on their expectations like Mass Effect 3, Assassins Creed 3, diablo 3 or darksiders 2. But I feel it definitely had it's fair share of real gems.
To me this year and last year seem about the same regarding quality. Just that it's harder and harder to not grow more jaded with every year.
Ah, you have some good points that I had forgotten about, though a few of those are just good cheap indie titles that I'd only consider great due to their cost. And as great as Xenoblade is, I have a very hard time counting it as a 2012 title. It's a game that came out in Japan in 2010 and Europe in 2011. America just slacked on getting it like crazy. As I recall the first season of Walking Dead did win a lot of awards. And I've heard that Journey and Amalur were great too, but I don't own a PS3 to verify that. I'll definitely give you Borderlands 2 and Guild Wars 2.
I'm not very high on Asura's Wrath or Mass Effect 3. But yes as you say it was the big hyped titles that truly disappointed. And while there were good games, there wasn't anything that really blew us out of the water (at least for me). But I feel that this year GTA V, Watch Dogs, and Fire Emblem could all blow us away and cause us to remember this year fondly all by themselves (assuming the first two live up to expectations, and I'm pretty confident that GTA V will at least).