Part of the issue is probably the rather byzantine nature of the forum. The number subfora is bewildering, and nowhere is there a 'new to TacComms?' section or anywhere which explains forum jargon like EpicUK and NetEA.
It takes quite a lot of time and effort to dig into the forum and work out where things are, and while questions like the opening post tend to be answered politely, it's much like asking an eldar – you get three answers, all true and terrible to know!

Regarding playtesting, I've got a group keen to playtest the Leviathan list against everything from Guard to Marines to Tau. We just need a few pointers, but the Tyranid subforum is pretty quiet except for the Onachus thread, which our new Tyranid player isn't interested in (he wants the new stuff so he can match his 28mm scale army).
Regarding development in general, the majority of lists have settled down, and most discussion is now revolving around very minor changes. This is good, as it implies most of the lists are pretty balanced, and that people are happy with them.
Unfortunately, it also means that there's not a critical mass of people to create much discussion of the remaining lists – notably Squats, and Tyranids.
Five to ten years ago, the core lists still needed testing, and – for obvious reasons – lots of people could help, and that warranted so many subfora. For these orphan lists of long OOP or otherwise rarer armies, I think they'd benefit from being grouped.
TL;DR
My group and I would like to get involved and be more active in playtesting – I'm sure there are more people out there. Please help us assist by putting up a '
this is what the NetEA want you to playtest' post somewhere obvious
