Upgrade cycles are at the whim of Adobe - when anybody on the forums know, you'll know.
Please step into the time machine...
RoboHelp 9 was initially released in July of 2000. (so Adobe monkeyed with the version numbers when they acquired it)
My guess is that indeed there will be an Adobe RoboHelp 9 (if Adobe chooses to call it that - until they do, it's always referred to as "next". So "RoboHelp next")
Presently I'm unaware of an Alpha or Beta, but I'd be totally surprised if they weren't working on a next version.
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