You will continue to add units thorughout the game -- but at a cost. Most, if not all of the early units end up having better stats than the later ones. That's not to say it's impossible to get by with the later units, but you are sort of shooting yourself in the foot.
Also, if you've lost 4-5 units in a single battle, reset. The time you save by continuing without them isn't worth it.
There are some give and takes with the changes in Infinite. I actually liked BioShock's "FUCK IT, YOU CARRY ALL THE WEAPONS AT ONCE" design choice, as it allowed me to experiment more with weapons I normally would have used maybe once or twice. I understand why Infinite only let you carry two weapons at once, but that led to me using only a small handful of early game weapons I had already upgraded.
I thought vigors were a fairly major improvement over plasmids. Each vigor had advantages and disadvantages depending on the situation. In Bioshock, there were simply too many plasmids that basically did the same thing. For example, there were three "aggro" plasmids -- one for splicers, one for turrets/cameras, and one for Big Daddies. Vigors cut out the redundancy.
I could go further, but I'm too damn tired today to write a thesis comparing BioShock's combat to Infinite. I think Infinite fine-tuned some problems found in BioShock regarding enemy health and plasmid redundancy but could have done more.
It looks fine to me, but I won't know what to think of it until it's sitting in my hands. The touch controls could easily share the fate of Sixaxis motion support if they're not implemented well. It'll be interesting to see how things shake out.
The Last Guardian. Watch_Dogs and Dark Souls 2 are massive blips on my radar, but I can't see a scenario where they aren't shown at E3. The Last Guardian, on the other hand, is an enigma. Sony won't say anything about it other than confirming the game isn't dead. The only logical conclusion I can make is they transitioned The Last Guardian from PS3 to PS4, but couldn't say anything before the PS4 was announced. An E3 press conference would be the perfect place to show off this game, but I'm also sleep-deprived. For all I know, I could be living in fantasyland. Still, it'd be pretty cool if fantasyland and reality coalesced in this instance.
@starvinggamer@golguin@ghostiet I've already spent hours scouring message boards to make sense of the BioShock Infinite ending (including the GB one), but thanks for facilitating the process for other people. People like you are the reason why the Internet is pretty great :).