OK, trying to collect some info, presently it looks like this:
EW: All three books have addendum in the form of a free pdf download:
http://www.flamesofwar.com/Portals/0/Documents/ThirdEdition/EarlyWarThirdEdition.pdfERgo, they are v.3 ready.
MW: nothing v.3 about it. predictions as to the release of the MW books in v.3 are as late as spring 2014. Nothing concrete. No v.3 downloads. This means that everyone will have to remember to update the special rules on their gear from the other two periods (ie German 10.5cm howitzer "Breakthu Gun"). However, all the points will be a bit off.
LW: completely v.3 at this point with just a few stray pdfs that need updating.
My personal opinion is that I'd play any of them. I don't think the point system is that precise and I am also certain that player proficiency is the most important factor. I'd be willing to say that a swing of 10% in points for an entire list doesn't really matter much on the tabletop.
I was reading my MW books...I have to say that it is a great period with the most variety of gear as a total, from EW gear that's hanging on to LW gear that is brand new. and plenty of armies that are transitioning from 1939 to 1943. Interesting stuff.