Papyrus is actually shipped with Eclipse Juno SR1. For both the standard release and the Modeling Package. We haven't changed anything here.
Papyrus is not installed in the default Modeling Package (It has never been), but you can install it with "Help", "Install Modeling Components", "Papyrus".
"The most basic procedure for installing Papyrus consists in installing the Eclipse Modeling Package for your own platform.
Then, you have to use the discovery interface ("Help" => "Install Modeling Component") and select Papyrus."