Yes, I wonder why that is, guess we have to be patient, hope thats not the end of KT!
(maybe notareal knows whats going on?)
You can find kerkythea on some pages like filepig
(http://filepig.org/en/windows/kerkythea) but it is mostly not the latest version.
And even you have Kerkythea you will need the exporter (sketchup to kerkythea)and the materials and lightings fixtures for Kerkythea.