I started to look back for the earlier threads, but they were a long time ago! Anyway for any one who is intrested I received this today.

This is a courtesy notice to let you know that
the beta that is about to be launched and that Pre-order offers end August
2014. 

 
They started taking pre-orders at the end of 2013!

FWIW - drumcore posted on their forum today - 3 more rounds of beta left for the Mac, then windows version several weeks later.  I'd be shocked if this was released before July 2016.

Kinda weird that a drum prog (rev 4) takes a few years to release.
 
With the current pricing of drum progs, this seems extra kinda weird:  
 
DrumCore 4 Ultra ($599): Over 50 GB of DrumCore 4 software and drum content (valued at $199) and 9 DrummerPacks (valued at over $600) on a 120 GB USB3 SSD drive (valued at over $100) 

The cost overruns on this must be horrendous. Plus your state of the art concept takes so long to come to market others have left it way behind. Look at ST3, looks a couple of years out of date the day its released.

I think they said they would be releasing it on the 1st of the 4th month 2016

They have taken themselves off the radar and the only people still talking about them are irritated as can be.

 Since the last creation, the drum market is too competitive for their pricing.  After having the big Drum Core 3, most of it was audio loops and not so much drum hits. 
 It seems like there is this pattern when it comes to acquiring another developer's virtual instruments there is rarely any progression.
 I don't even have Drum Core 3 on my drive anymore.