Yep, I play it religiously. SO AWESOME.
You can get almost all the commonly used "unlock" weapons by completing the achievements for the individual classes. Other than that you can craft particular ones you want using recipes from the TF2 Wiki.
Sadly it's turning into more of a RPG with all of the new items but it's still fun to play.
The Wiki is good reading those as Jodi says. Worth have a trawl through there.
http://www.tf2wiki.net