Hmm, I agree this looks worrying. I was hoping for a well-made L4D2 clone. Well, I say "clone" but L4D2 is such a well made game that having simular mechanics in a diffrent game, such as Aliens: Colonial Marines should sound like fun, being in a diffrent theme, but this article does make it sound a bit skewd.
The video also shows Xenomorphs running in open ground towards the Marines, which seems far too lenier when they really should be hiding, waiting to pouce. I can only hope that was just the action-packed trailer and that the aliens will have far better stealth abilities.
Level design would play a major part, as it has done in L4D2. The wrong kind of level can lend weight to one side or the other. That, and making the Xenomorphs spawn anyway out of sight of the Marines, as the Speical Infected can do in L4D, would be a massive advantage over set spawn points.
Lets hope these are small flaws which will be ironed out. I would be dissapointed if the multiplayer was stagnant.
"I am justice incarnate: Brought to this world by forces beyond your comprehension. A cleansing storm to sweep across the land and purge it of your foul presence. I am Dust!" Dust to General Gaius, Dust: An Elysian Tail.