Microsoft has released more information about the standardised hardware foundation on which Windows Phone 7 Series will work; these will apparently be the minimum requirements for a device to get the WP7S approval.
And based on what we've seen, these are likely to be pretty high end. Istartedsomething's Long Zheng posted a slide that details the minimum specs as follows.
A four or more contact point capacitive touchscreen (no more resistive then!) with a resolution of 800x480 or 480x320 pixels, AGPS, Acelerometer, compass, light and proximity sensors and three hardware buttons (start, search, back).
As for the rest of the hardware, the phone will need to have an ARM v7 Cortex/Scorpion or better processor, a DirectX9 GPU, 256MB RAM or more, 8GB Flash or more, no user upgradable microSD slot and a 5-megapixel camera with flash and camera button.
Zheng also published photos of a Samsung Windows Phone 7 Series smartphone - that shares the same form factor as the i8910HD - that came with a gorgeous AMOLED (or maybe Super AMOLED).
LG and Asus have also confirmed that they will be selling WP7S although the fact that it won't support multi-tasking because, like Apple pointed out for the iPhone, multiple apps might make the system become inconsistent (although that will come later).
The Windows Phone 7 Series is impressive and will help Microsoft finally catch up with the rest of the competition. Technically there's nothing that prevent Microsoft from actually releasing phones based around this. However, the company is likely to hold fire until it is sure that it has everything in place.