I don't see why people keep calling this (and the Fascinate) a mid range phone because of its 800mhz processor, though the Fascinate has a 1ghz. The 800mhz is actually faster than the previous Snapdragon 1gz. It's like comparing a P4 3.6ghz to a Core2Duo 2.6. The Core2Duo is actually faster despite the ghz rating. That actually scares me because Bing is rumored to only be on mid range phones, not the high end. So unless Verizon is going to release some super duper phones after this one (that blow this out of the water), looks like Bing can make it to any phone.
But back to what you were saying, the only downgrade there would be is screen size (I assume), and your preference of NinjaBlur to Sense.