That won't be the case for everyone. The installer already indicates that it uses QT for its UI, so anyone using KDE for their desktop should't have anything to chase. I installed Sigil on my Kubuntu 10.4 system without any incident or missing libraries, and I look forward to putting it through its paces. I hope that, at very least, it provides a good ePub validation tool for imported (X)HTML.

Having said that, it would be nice if ePub export was possible from Quanta; however, IMO the open source tools that would most benefit from ePub export would be Scribus and maybe OpenOffice.org and/or KWord.