Currently there seems to be no direct way of updating virt-manager translations (how about Fedora's Transifex?), so an updated fi.po should be attached as a hg bundle.
Created attachment 294046 [details] Updated fi.po as a hg bundle
Hi, I'm looking into using transifex. I'll post back here with more info soon.
Thankyou for the translation. This is built into virt-manager-0.5.4-3.fc9 and applied upstream