Miller: he's ready right now. He's flat out dominant at the AHL level. Yes, he makes mistakes every now and again, but they're mistakes of effort and are far outweighed by his dynamic play on the ice.
Fast: also ready right now. As I've said ad nauseum, he was ready defensively out of camp (to the point that AV gave him regular PK time), and has really been turning it on offensively recently, with a goal per game over his last seven. I don't like to make comparisons that seem obviously tied to nationality, but I see a fair amount of Nyquist in his game. If not for injuries, I think he might already have a spot on the Rangers.
Lindberg: may be ready right now, certainly could be ready at the deadline/coming out of camp next year. I mentioned early on when I was watching more full Wolfpack games that he wasn't yet the dynamic force you want to see at the AHL level, but that he was making lots of little subtle plays that were very encouraging. Recently, he's showing more of that dynamism and it's translating on the scoresheet.
Kristo: not ready right now, likely ready sometime next season. The kid is a natural scorer, who just knows how to put the puck in the net, but as others have mentioned, he continues to have WTF? type mistakes - think Brad Richards last year to get an idea of how bad - which I think put him behind all of Miller, Fast and Lindberg on the depth chart of callups. (Actually, if he were on a Buffalo or an Edmonton, I could see him playing in the pros and making those mistakes in the pros.) For those who are worried about his age, remember that he was a four year college kid, who suffered a really bad injury; I wouldn't start worrying too much until about his development until this time next year. By then he needs to be a legitimate call-up option.
Allen: is ready right now. Steady, smooth, unspectacular - not a lot of offense (although he has some potential to develop more), not a lot of grit, but a good skater and smart player who is a very solid defender in the AHL and would not embarrass on the 3rd pairing in the NHL.
McIlrath: is not ready, and may not be ready next year. He definitely has flashes of "wow", primarily in the physical aspects of his game, and he also has started to show offense that encourages you that he could have untapped potential as a bomber from the point that could develop late a la Chara. But he gets beaten to the outside a lot and falls down way too much when trying to pivot - it's not that he's a bad skater (he's actually quite good for his size in terms of speed and agility), but he loses his balance in a way that occasionally reminds me very uncomfortably of Hugh Jessiman. Now, it bears repeating that he's lost a lot of time, including his last several games, to injury (but then again that's a concern as well) and big defensemen can take a loooong time to develop (again, see Chara), so we need to be patient. I also think he feels the pressure to perform and that may play into him trying to do too much, which in turn may translate into some of the falling down and losing his guy. But I'd be lying if I didn't say I have my concerns about him long term.