Barricading isn't limited to the "barricade" action on doors and windows.
You can make your own mobile barricades by pushing stuff around.
Shopshelves are very good for this.
You can make your own little forts very easily.
A simple "wall" setup (shown locked from the inside).
A slightly better one, to prevent zombies from seing who is inside (shown open from the outside).
A better one, with a "mobile door" (shown here closed from the outside) :
Since you can push stuff around why not barricade the street to make it even safer?
This is not new, you can do all this in alpha 2.0.
Incidently, some of these screens show a new 2.1 feature I didn't mention...
End of post.