...As far as the extended battery and larger cover, I agree there are many who would want that, I'm just playing devil's advocate from the company's point of view and not seeing a large enough projected consumer interest based on the increased price of production.
Decisions, decisions...$105 is about the price of (2) 1900mAh batteries, but here's a 3600mAh (from a reputable company) with larger cover:
[HLI-Z710EXL] Buy Mugen Power 3600mAh Extended Battery for HTC Sensation / T-Mobile Sensation 4G with Battery Door
http://www.youtube.com/v/s6moi12ZL-4
$95 at amazon.com: