I have Ubuntu 13.04 DESKTOP version and for some odd reason I'm told that the Unity launcher cannot be moved to the bottom of the screen because of several reasons:
1. Canonical wants it there so it fits with their overall design goals, namely when it comes to touchscreen devices and netbooks. This in my mind totally ignores the fact that most Ubuntu users are DESKTOP users. No matter what Canonicals long term goal is, it surely mustn't be at the expense of needs of their core user base.
2. Most monitors are widescreen, the launcher is more compact where it is. This is not only taking away the users choice, but is also a wrong assessment. Widescreen monitors can sometimes be rotated on a pivot, giving it a portrait aspect. By displaying the Unity launcher on the left side it takes up a lot of space. Many desktop users have multiple monitors, and having the launcher on the left side of each monitor is very awkward. Also, many websites are catered to fit on a half 1920 display, so you can have two browser windows open side-by-side with all content visible. The placement of the Unity launcher takes away the horizontal space meaning there's less room for each browser window, and you'll see the right side of the web pages being occluded.
Any suggestion to simply hide the Unity launcher, or "Canonical knows best" or "get used to it" are unwelcome and totally ignores the above points.
Linux is about choice. Canonical's stubbornness with the Unity launcher placement is inconsistent with what Linux is about.