You just have to install the .deb package of Adobe Air from Adobe’s website. Then you just run the people power .air package using the appinstall program that comes with Adobe Air.
So yes, it runs natively, no WINE or other emulators needed.
If you are on 64bit here is a guide to install adobe air:http://www.jamesward.com/2010/10/14/install-adobe-air-on-64-bit-ubuntu-10-10/
For 11.04 I don’t know, but should work the same way.