The update for the L4B zombies is still being worked on, but lots of optimizations/bug fixes/additions were added. From what I can remember, there are:
-New appearances
-More features
-New events
-More SFX
-Improved code
-New zombie types
-Upcoming 2nd extension pack with unusual zombie types
I'd say this update will come out in a few days or another week, depends on how much I can get done now.
My guns in my SWeps pack received a facelift with new models and better SFX. The FAMAS and SCAR-L are now burst fire instead of auto, and some new weapons will eventually get added. The Glock has been replaced with the M1911, and there's a new LMG variant along with a new shotgun (I forgot to show the new Remington 870 in the preview). What I have left is to finish adding the new weapons and add scope functionality for the snipers and new rifle.
Here's a preview for the new models: