Metro 2033 was a brilliant game......I don't mind linear / story driven games. People talk a lot of times like that's a bad thing, but some of the best PC FPS games developed (F.E.A.R., Half-Life2) are developed the same way. I don't mind it if it's done well, and Metro, IMO, has done it as well or better than anybody.
I'm pretty stoked about Last Light, but I'm a little apprehensive about it appealing to wider audiences. The original had the perfect combination of gunplay, story, and pacing.
It's also a good idea to keep in mind that the original game didn't have a huge budget and big development team, which makes what they accomplished all the more impressive - - and they clearly had hardware-pushing graphic quality in mind when they designed it.