I am still interested, but was unsure of the status of other implementations. Given not much new, perhaps I should go ahead with it?
Last week I was also considering the possibility of making a Spark package for LDA. The aims would be threefold: have more algorithms (I have been contact by a couple researchers basing their work on the Gibbs LDA I worked on, plus I will likely be using it in my own PhD starting this fall), a good place for relatively new/unproven variants, and then pull the best into spark. I have been pretty busy so haven't gotten around to that, but it has been on my mind.
When I get time this week, I will take a look at the current source and what I have to see how much work it would take to get to something that could make a pull request. Although FastLDA/LightLDA might be algorithmically better, I think that what I have would be a good starting place at least.