Split screen (SP campaign) coop will not happen and I personally enjoy coop in R2 more than R1 (coop).
They can rework current coop for 2 player offline if the demand is high, but I doubt that too. I saw a lot of split screen coopers online yesterday.
So I finished the campaign. Gfx are way underrated, and I blame the kitty guy. I watched gamersyde videos before playing, and I too thought the indoors were lame, outdoors were OK.
Now that I played the game, while there are a couple of really lame stuff indoors (like monitors and switches), the graphics are consistently great save maybe the Canyon. Water animation and interaction is best, although looks a little muddy time to time. Streaming is excellent, so are checkpoint restarts (with at most a couple seconds of blank screen).
As for gameplay, weapons are greatest ever. I have never seen a game with so many fun weapons. The last champion was R1 naturally. It's unfortunate that two out of three of my fav weapons from R1 didn't make it.
Bullseye tagging is now almost useless. Likewise for Laark altfire, which is only useful for a swarm of drones. To be fair, that was really an awesome show, but no excuse for removal of original heatseakers. Bullock was fun in MP, unnecessary in SP.
Fortunately the remaining of the three, Auger, is back and even better. Magnum is the best pistol, maybe even the best weapon ever, and Marksman, to my surprise, is a lot of fun for shooting at running hybrids. Wraith, Splicer, and Fareye are also welcome, though the last one took a little hit compared to the original for some reason.
The wheel is greatly missed. It's really painful to throw out so many fun weapons. I don't buy the balancing shit bit. Two weapon system is for "other" games, not Resistance.
Minibosses of the original all took a hit, partially thanks to slightly misplaced obsession with scale. Titans and Stalker encounters were much more fun in the first one. Now totally gimped Laark is forced to you to take a large number of them on a single encounter.
Which brings me to my biggest problem with the game. It's all about taking damage. The new health system, while most natural for Hale, totally ruined some great aspects of R1. There is little you can do to avoid bullets at medium range. Chimera bullets are fast, accurate and powerful. I don't really mind dying (and felt like R2 difficulty was just right), so powerful is fine, but playing while screen is constantly flashing red and Hale making "Agh, Ugh" noises is not fun. As if the upgrade of Hybrid Bullseye was not enough, they added enemies carrying laser turrets and increased number of minibosses. On the plus side, large number of minibosses indeed often makes you feel cornered and hopeless, but the way you end up getting out of the situation is far from satisfactory.
Another side effect the new health system is lack of scary moments. In R1, you don't carry healthpacks (naturally) and quite often continue with one or two bars, at which point even the smallest enemy can be deadly. If it was up to me, I would reduce the health regen speed significantly, halve the Chameleon damage, but increase the number of them. Water encounter was great.
Humor also was absent because of the depressing mood they were after. Insomniac said they had been trying hard not to insert jokes in the first one, luckily a couple of them had slipped by. No such luck this time. The English soldiers are greatly missed.
Anyway, while medium range combat fails short of what R1 did, short and long range combat makes up for it. All in all, anything that involves large number of Chimera totally delivers. That's the right notion of scale.
As for story and storytelling, I totally loved them. Gameplay to cutscene transitions are greatest. I guess some may be bothered by lack of control in FP camera, but for me it's much more convenient than Half Life's storytelling. Characters are totally unmemorable (including the new Hale) which is considerable worse than what R1 did. But I'm totally OK with that, considering the direction they took. Make no mistake I do miss the English, I'm just OK with those particular characters being unmemorable.
I don't agree with the comments that the game needs a little more polish. All the problems I have with the game are because of fundamental design choices they made. Besides that, their production workflow is clearly working, and they still managed to produce a huge game withing short amount of time. It's really unbelievable.
What I do feel is that Insomniac don't play to their strengths, except for weapons. All the gameplay changes seem to be influenced by other popular games. They have a scifi setting, awesome tech and greater freedom compared to a game like CoD or Killzone. They are not doing what they did with Ratchet 2/3.
In short, it's still the best shooter I have played in a long time, but it's not the game I was hoping for after R1.