Thoughts so far: I'm amazed.
I'm about 5 hours into the campaign and it's maybe my favorite COD campaign ever, and that includes COD4. We'll see if I'm still feeling that way after I beat it, but so far, goddamn. It outdoes Mass Effect in several respects and still feels like a true COD experience, plus a little bit of that Naughty Dog feel. Infinity Ward actually lived up to their promises on single player. The Retribution feels like it's alive, I care about the characters, and the Jackal missions are really, really fun. Can't believe there's so many of them.
MP feels much more solid than the beta did. Just waiting for them to patch up Infected and put it back in, and I'll be playing all the time. Nice of them to have double XP weekend and Terminal 24/7 in the meantime. Not the best MP ever, but different enough for me to play until 10th Prestige at least.
Zombies in Spaceland is the most fun I've ever had playing COD Zombies, period. They nailed it. Glad that they're going wacky instead of dark and serious for a change. Music is great, seems really deep yet accessible, voice acting is awesome, weapons are solid.
Modern Warfare Remastered is obviously perfect in both campaign and MP. Would've gladly paid $80 for this alone, so it's awesome that we got everything else in the Infinite Warfare package included. This is way more than enough to last me until next year's installment.