As per WPCentral (original sources - Microsoft blog and Engadget)
http://www.wpcentral.com/microsoft-details-features-and-performance-coming-winrt
http://www.wpcentral.com/microsofts-windows-rt-surface-tablet-launch-october-just-199
Battery Life:
In connected standby mode - 320-409 hours
HD Video PLayback - 8-13 hours
Price Point:
$199
Physical dimensions given in the link.
I would think the price point is a bit low, maybe anywhere between $249 to $349, but if they can pull off any of the mentioned prices they may sell a crap ton of these. Battery life specs seem impressive if accurate.