The biggest "console port" sign to me is with the graphics. I didn't even notice that controller icon there; good catch. The control is one of the biggest problems with the game I find, though I am not entirely sure that's due to it being a console port. The way you walk is just not as fluid as most other games, and you seem to wobble around a lot more. Compare that to Borderlands, where the control couldn't be much tighter.
The reason the game is better for co-op is that the game would be quite lonely without a second player, and since this is a game about survival, you will have to help each other out. I died in the video, but because my brother also died at the same time, he couldn't come over and help me. Interestingly, just like Borderlands, you lose about 10% of your cash whenever you die - something I didn't even notice until I re-watched the video.
You can also trade items with each other, but up to this point I haven't found the need to do that. Later on, mods can be crafted though, and one player might have something the other needs.
In general though, given that this is a co-op game, it misses the mark in a couple of major ways. In Borderlands, cash is split between players, while here it isn't. Each person fends for themselves. Collector items that are found throughout the landscape also need to be picked up by each player, which can become a hassle because you will need to tell your friend/s to pick something up so that they don't miss out. Likewise, if one player begins a quest, it doesn't always appear that obvious to the other player. You will still see the NPC banter, but that quest will not automatically become your active one. It's just these small details that can complicate things.
At $50, I don't think this is a port worth the cash, just because it lacks a lot of polish. It puts you into the game without a lot of explanation about how certain mechanics work, and you end up looting a LOT of stuff that you are not even sure has a use. Weapons also leave a bit to be desired, because you constantly need to find replacements. It's realistic that after five or so zombies, your baseball bat is broken, but it still makes for semi-tedious gameplay. Whether or not upgraded weapons degrade at a slower rate, I am not certain. Upgraded some last night then hopped off (brother is not enjoying the game as much as I am).
There's also a problem of too many quests. About a half an hour into the game, I had five active quests, and it just left me confused as to what order I should do them in. Most of them so far are errand quests so far, but since I love exploring, I don't mind them that much.
Like Borderlands, the zombie difficulty does increase when more players are introduced, but I am not sure to what extent. In Borderlands, enemies as a solo player were almost too easy, so the same might be true here. We've only died once, which was the death in the video.
I guess in general, they made the game co-op because it could be. There are lots of zombie games out there that have co-op, but this takes things to the next level by giving you a large landmass to traverse and kick ass through. So far the game seems like it has a lot of freedom. I just wish it had some less niggles that I've mentioned, because it could have been a must-have if certain things and mechanics were better implemented.