I've only played a little of the demo for STALKER and MY first thought was: I've seen this game before -- F.E.A.R.!! Well, it does also have some similarity to HL2, which I've completed and played at least a couple of times.
But, that's beside the point I want to make. Here's my point: With Microsoft and others releaseing the game development TOOLS to the public with which to create games, how in the world will people avoid similarities??? There's no way! All that can be done is to try to make the experience different enough that you don't actually feel like you're playing a copycat game.
I don't really have an educated opinion on whether anyone stole anything from the other games for STALKER, but, I wouldn't be in shock to find out that there may have been things that were intentionally included. Think of it this way: How many TV programs, Movies, etc, have you ever seen where someone did a 'send up' of another program? I'm even seeing comic strip writers referring to other comic strips and using characters from the other strips these days.
I can only imagine that it would be deemed 'illegal' if the 'copying' is done without express and written permission or with a very transparent intent to simply show 'honor' to the other content.
Well, there's my two-cents worth and a little more.
