The plot and development of the M&M universe is discussed in the main here: what they've kept (most of the fantasy stuff) and what they threw out (all the sci-fi stuff, apparently!? That particular installment must have passed me by). Innovations, inspirations and reasons for revamping M&M are also highlighted. Intriguingly, we're briefly told that a possible prequel for M&M might be in the pipeline:
"And we are already thinking of a “prequel” saga that would let you delve into some of the more obscure mysteries of our world.
Whether that would take the form of a HOMM game or an alternate game in the M&M series isn't elaborated upon. Shock. Anyway, it's all well worth a read.
Oh, and apparently the best praise this new M&M universe has had is this:
Which sounds about as committed a response as you can expect, given the information we've had so far. Yet it still sounds good to me.