It appears the 48" E-series is also now available from walmart. Something I have noticed, is that the number of dimming zones is much lower than what was said to us. My guess is the number that was listed for each series (16, 32, 64, ect.) is the maximum number of zones possible in the series. If you look at these two models:
The 40" model has 5 dimming zones, and the 48" has 6 dimming zones. Still for the price, you can not complain.
So for those of us shopping at the lower end of the spectrum, the differences between E and M series are:
M series likely to have more backlights for a given size. (Up to 32 - for the 80" model. We don't know how many the smaller sizes will have.)
M series likely to have higher refresh rates. The E above has 120Hz, would an M of the same size be faster?
M series has 802.11ac vs 802.11n in the E.
M series gets "Active Pixel Tuning" which "delivers intelligent pixel level luminance adjustments to further increase contrast and picture detail accuracy".
M series is all 1080p, E series has some 720p.
Interesting that the Walmart price is ~$50 more than the press release price. The price on Vizio's site is $450. So the press release was off by a bit.
Now to impatiently wait for the Ms to be released so I can obsess over the real specs.