I'm curious as to how it compares to Space Hulk. Granted, I haven't played it before but from what I've heard of it and seen of Gears it looks like they just changed the setting.
In the sense that it's a board game about a bunch of "space marines" shooting big guns at "weird aliens" in relatively tight quarters, and potentially with scenario-driven goals to accomplish, then yes, I imagine it will be quite similar to Space Hulk. Also fairly similar to just about every dungeon crawl-style board game ever produced, if you relax the sci-fi theme as a requirement.
I expect the meat of the differences will be in the mechanics. For example, one could easily say that Space Hulk and Doom were the same with the setting changed. Everything that we know about Gears so far is also true of Doom (except the co-op bit, but Space Hulk wasn't co-op either.) Having played both Space Hulk and Doom, I can say with certainty that they are very different games. Hulk is a tactical combat game with varying scenario-driven goals, while Doom was a suspenseful survival-horror themed game where the primary goal was almost always to get through the red door alive (there were quest-specific details, but getting to the door was an important part of planning your marine strategy.) Doom had ammo limitations, Hulk did not. Etc.
You can make any two things seem identical if you generalize enough. Apples and oranges are both (quasi-)spherical fruit, after all. I strongly expect that Gears will prove itself distinct from other sci-fi themed dungeon crawls as time goes on.