You do realize that in order to develop a larger (physical) battery, which is what one over 1900mAh is, the designer also has to develop a larger battery cover, which on the Sensation is a unibody all-in-one? That means new antenna for all wireless communication, etc, since those components are in the cover. Once that's done, the cost increase of the battery cover itself would set the combined cost of the battery and the cover together too high for most to want to purchase. I would imagine that they would need to sell a couple thousand combo units to offset the cost of R&D, marketing, production, etc, which is a number they probably would not reach given that the combo unit cost would be close to doubled. Would you pay $150 for a 2700mAh battery + cover combo?