Unity launcher -- is it available as a separate package?

Unity is available for 10.10, you just need to install the ubuntu-netbook package

Unity is also available for 10.04 through the PPA named canonical-dx-team/+archive/une

In both cases this will add a new "Netbook edition" option in the login screen. I don't think the dock is available as a stand-alone package.

More information and detailled installation instructions can be found on the wiki : https://wiki.ubuntu.com/DesktopTeam/Unity

The 2D Unity project comes with unity-2d-launcher which can serve as a stand-alone unity launcher

PPA: https://launchpad.net/~unity-2d-team/+archive/unity-2d-daily