My site is currently run on WP 1.3 Alpha 2. I am setting up a WP 1.5 test section so I can play around before I do the real upgrade.
I created a new folder, extracted the tar.gz file there, created a new database for testing, ran the SQL dump of my WP 1.3 Alpha 2 - so I could have some real data in there. But then, when I looked at the site - http://17thdegree.com/wordpress15 - there are no styles applied. I didn't change anything - to my knowledge.