7 of the 9 are games. If your friends don't play games, they might not be wowed. Eyewitness is a great app, but it's not really anything that can "justify your purchase", since it's not anything that can't be done on a web site.

Apps worthy of consideration, if not for diversity's sake, are:

Flickpad

Reeder (I go through my RSS feeds faster than on a laptop)

Brushes (the playback is especially cool)

Penultimate

Any VNC/Remote Desktop app (Not very innovative, but showing that made 2 friends run out and buy/order iPads) or any app that turns the iPad into an external monitor

Roambi

Instapaper Pro

Apollo News