The book in progress (Plasma Rain) was intended to be the series conclusion. At over 100k words, it isn't yet in sight of the ending, so we may decide to halt at the end of Part VIII and wrap a cover around it.
If that happens, we could have a release in 3-4 months. But that would leave a positively /brutal/ cliffhanger. We ended Black Hawks From A Blue Sun in a similar way, which, considering it took two years for the sequel to publish, was widely deemed an act of cruelty.
We're doing some major soul searching right now, regarding what extra resources we could commit and how quickly we could bring the conclusion to market. If we determine that a finished, *quality* finale can be produced in twelve months or less, we'll release the current work.
Thank you very much for reaching out! I know this wasn't the definitive answer you might have liked, but please know your interest is helping to steer the decision. An answer will post on our blog site shortly.