I really want to purchase it here.

Neither Firaxis nor Take-Two curently have a contract with GOG.com, thus I wouldn't hold my breath.
I do hope it comes though, even if I already have it.

Unlikely. At least for the time being.

Unfortunately it is a Steamworks game. I don't think any game has had Steamworks ripped out of it to end up on here.

Alan Wake?

I recall someone asking them about bringing the X-com games among others to GOG but there only response was a generic "we try to get our games available on as many outlets as we can but for now you can pick them on on steam"

Stranger's Wrath?

Not to mention the Humble Bundles, which regularly have previous Steamworks exclusives.

Yes, Alan Wake is the first to have Steamworks ripped out.

Edit: Didn't know Stranger's Wrath was Steamworks...

But aren't those two SP exclusive games?

X-Com has a multiplayer component. (Awesome game, btw)

I stand corrected. I forgot about those games. It doesn't happen often though but this game is one I definitely want to see that happen to.

I think it just requires IP to connect to, or was that for the Consoles versions? At least the E3 multiplayer videos I was watching seemed to be like that, thus it may not be using Steamworks for the multiplayer component.
Now the question becomes, can you play multiplayer cross platform with it?

And I had hope when I read the thread title, hoping for sensational coming true rumours...

STRANGERS WRATH IS ON GOG???? WAAT!!

I love when that happens.