I've been compiling the latest tree of Arora browser code against the latest Qt-4.5 qt-snapshot from labs.trolltech.com on my Mandriva 2009.0 system since Arora-0.5 was released on Feb. 20th. I compiled the latest arora.git 0.6 this past Friday and I've been using it for two days now without any problems. It supports Flash, Javascript, and the mplayer-plugin, so I can watch youtube, CBS and NBC news with it... I'm using it right now.
Firefox 3.0.7 shows 71/100 on the acid3 test, but look at Arora-0.6: