I'd be very interested in reading people's replies to this too.
I recently moved back to Windows after a long time on OSX and have installed NexusFont which seems to work nicely so far but, as with ginkgo100, something a bit more powerful would be better. For me, some kind of "smart categories" feature that could automatically group fonts with similar characteristics together - e.g. serif vs. sans serif vs. decorative - would be very useful.
I didn't know about SkyFonts so it would be nice to know how it works with things like Scribus, Inkscape and GIMP. (Trial and subscription fonts are apparently "kept hidden and protected elsewhere on your hard drive" so how do you access them?)