The example sample is not really designed as a showcase of Impala for users, but more a testbed for features aimed a Impala developers.
The easiest way to access the examples is to check them out directly from trunk.
svn co http://impala.googlecode.com/svn/trunk/example-sample example-sample
Then open an Eclipse workspace in the new example-sample folder, and import all the projects into the workspace.
From within Eclipse, run StartServer as a web application. Then connect using the URL:
Wiki: DynamicProperties
Wiki: RunningSamples
Wiki: StartServer
Wiki: WikiHome