This will become a collection of some tips around the new plasma desktop. Feel free to tell me if you think there's something missing.
Containments
If you zoom out your desktop you have the possibility to add a new "activity", or better a desktop containment (the word activity is better, you will see). Zooming in again you can switch between these activities with Ctrl+Shift+p or Ctrl+Shift+n (previous and next). Now you can add whatever plasmoid you want. Note though that in every activity you can add different plasmoids. And that's the point. You can even have different wallpapers on them. Suppose you have one activity, where you want some picture frames from your family and a plasmoid with your favourite garfield comic. And maybe a note plasmoid with your shopping list.
Now you can have another activity with maybe a newsticker, the calculator and the folderview linked to your favourite files.
Folderview
There are so many possibilities with this applet, i'm sure i will miss some of them.
At first, sure, you can let it show your desktop, just like the old desktop. Only that it is limited to the size of the plasmoid itself. But you can also link it to every file you want, no matter where they are, local or remote. Whatever ioslave kde has, folderview can use it. Together with the filter there are WAY to many possibilities.
But some nifty things: if you drag a picture out of the folderview to the desktop, you can automatically add a pictureframe with that picture you dragged.
Or, you have 2 folderviews with different locations, maybe one local and the other remote. Now drag a file from one to the other plasmoid. Why use a file manager?
Icons
Much too often discussed... but some things i discovered. Simply drag an icon from the menu to the desktop or the panel. There you have your old icons.
More to follow soon