I haven't heard of a possibility to export QV - animations to ppt or avi.
For our screencasts we used http://www.utipu.com/tipcam-download/, but there are uncountable options on the web to make a screencast.It supports avi and flv.
As far as I am aware there is not a native option in QlikView. I use a product called Jing that is made by Techsmith. There is a free version of this, but you need to pay a small amount if you need to create .mp4 content.
I have used this to create the QlikView Videos on my web site:
The quality is higher when saved - but YouTube squashes it a bit on upload.
Post back if you need assistance with the settings or anything.
Not 100% sure this is an option but you can integrate a Qlikview object directly into Power Point via the OCX Connector (download from Qlikview.com) - it certainly works for traditional QV usage but whether it can handle animated objects I'm unsure.
You would of course need to be presenting from a machine that could see the Qlikview instance holding the .qvw.
For simplicity I'd recommend following Steve's suggestion.
All the best,
Matt - Visual Analytics Ltd