The most important tidbit is this:
"The rules in our current range of Warhammer 40,000 codexes aren’t compatible with the new edition of Warhammer 40,000"
Can you believe it? I can't. The downside is the money you've spent is wasted..the expansions, formations, supplements, etc are all useless.
The upside is maybe balance will return to the
However it means my army selection is very much on hold. I have one more unit to paint to get to 18 for the Inner Circle and after that I have built 25 more marines for a Lion's Blade which I will no longer be able to play (probably).
There isn't a lot of information on what exactly it will be like, but expect a HUGE upheaval in the game in a very short order.
Now, we sit and wait. Very impatiently.