I got a request to make a Slingshot video so I though I'd make one featuring some more Elementary apps which are currently under development like Plank (Docky re-written in Vala - this is a project of the Docky team and not the elementary team), Wingpanel, Beatbox (music player) and of course, Slingshot launcher.
So here is the video:
In the above video you'll also notice an updated Elementary theme which works with GTK3 too (but there's still a lot to do for the GTK3 version - the menus for instance look broken for now). I'm running Ubuntu 11.04 with GNOME 2, however Marlin is using the GTK 3 Elementary theme.
Remember, these are all under development so they are not stable nor feature complete! Read Cassidy James' comment for more info (and some insights on what will change).