I am Cox customer and noticed they just added StarzHD ondemand. Is there any news/plans for HBO HD ondemand or cinemax on any systems?

They had HBO HD on demand for sometime and had about 10-15 movies up, but a few weeks ago they removed it. I don't know why.

I don't have the link handy, but HBO HD On Demand has been discussed in another thread. HBO pulled it, not Cox.