Hum,,, I should think to keep an eye on a Postal II discount on Steam !

Awesome! Time to install it on steam and catch up!

2003 game getting a 2014 expansion... wonder if this is a record of some sort. Anyway, more Postal 2 sounds good to me, but I'll skip this expansion if it's indeed Steam-only; already have the game on disc and on GOG, not buying it a third time.

Regarding how you see it, there is an expansion for Age of Empires II 14 years after the original game's release. Sure, it's only for the HD version, but is there really that much of a difference between the original and the HD?

Well, IMHO those cases are different in the sense that the AoE game required for that expansion -- AoE II HD -- was a standalone remake: you couldn't buy it until 2013, while the Postal game required for its expansion has been available for purchase since 2003.

Nice sad if it turns out to be Steam only maybe it will come to GOG Galaxy in the future.

Are the cases really different? When Postal 2 was released on Steam it received a big update with achievements and stuff. Did the other versions (GOG, Desura, Retail) benefit from this update? GOG certainly didn't and I have no knowledge about the other versions. Isn't this expansion also Steam-only just like the Forgotten expansion?
The point I'm trying to make is that this version sold on Steam could, for all purposes, also be called Postal 2 HD.

Well they did say the Steam update would be coming to GOG in the New Year but that was awhile ago.
http://www.gog.com/forum/postal_series/steam_update_available_for_p2_will_come_to_gog_in_the_new_year

"Takes a look at the thread's creation date."
Yeah, wake me up when they finally release it. :P In their defense, they at least released the update for the 1st Postal.

Maybe so. I was under the impression that the main difference between the GOG and Steam version right now is the Achievements, but I haven't followed recent version updates there in detail. I still think the cases are different -- as AoE II and AoE II HD appear significantly more 'different' to me than original Postal 2 appears to differ from "Steam Postal 2"; a lot of differences between them having come from the A Week in Paradise mod, first released for Postal 2/Apocalypse Weekend 2006 or so, and integrated into the official game last year(?).

I'm not too sure about how different the versions are. What I'm sure, though, is that the Steam version has gotten many exclusive updates that are not available in any other version of Postal 2, making the Steam version, that was released just last year, a different one than the others. Just like the Forgotten expansion is completely exclusive for Age of Empires II HD, Paradise Lost also seems to be a Steam-exclusive expansion, at least for the time being. I wouldn't be surprised if the expansion came to GOG later, but to be frank, I would be surprised if Running with Scissors released those updates and the expansion for the old retail version.

Apocalypse Weekend sucked balls.I wonder if they learned anything from that.

I played Postal 2 on cd years ago, finished Apocalypse WE, A week in Paradise, Eternal Damnation and some mods... but I think I will buy the Steam version for this "new" release or expansion, just because it seems to be the most complete and exclusive version currently and to support RWS for making new stuffs for a decade game... and why not a true Postal III !