Hi Spore, good question.
In fact, Viridian Sun has not been entirely inactive since Perihelion. We (VS is me and David Tollefson, for those who don't know) got together and recorded the material for a third studio album in about 2001-2002 or so. The material just needed some editing and mastering, but because we were both so busy, it was never quite finished. We both think there's some good stuff on there, and we had some fun with varying the instrumentation a bit (the first two albums had been just Dave playing guitar and me playing synthesizers, while this one involved a lot more switching around between guitar, bass and synth), but the third album just sort of ended up shelved. Recently, digging through some audio archives when I revived my solo project Fabrications I found the digital files for that third album, and gave them enough of a listen to determine there is definitely a releasable album in there, in need of some editing and polish, but too good a thing, really, to just let it sit.
Furthermore, David and I have been talking about getting together again for some more recording sessions, and we've actually scheduled a couple of sessions at my studio the 22nd and 29th of this month. So, we have hopes for these being the foundations of a completely new album, which we would like to release in the new year some time, and depending on reaction to that new album (of which not one note has been recorded yet, I should clarify) we may go ahead and release the long-list third album, which I'll begin editing in the mean time.
We both have fond feelings about our collaboration and we remain good friends, so it's sort of a mystery why we haven't recorded together more often since the first two albums. My expectation is that we'll see at least three more Viridian Sun albums in the next few years (the recordings we're about the start, the long-lost third album, and a collection of rare compilation tracks and unreleased outtakes from the earlier sessions), and possibly a new Tollefson solo album.
Thanks for asking, Spore!