Sales took a huge hit due to supply issues. My guess is the common view by VZW is the device will sell half of what it could have, due to the shortage. Demand was very high, but supply has been very low- perfect storm for sales misery, considering several options are looming on the horizon. As of today, VZW still can not get supply to fill channels, yet alone cover current orders. Supply replenishment rates are so low, even low level demand would be too much.
I guess "half", since that is the common view from store managers in my area. My guess is the device will sell at least 500K, but due to the positive reviews, large VZW install base and also the Tmo high-end customer bleed rate, Inc would have easily busted 1M in customer sales.
added:
This could still happen, if the Inc's price point is lowered, in order to differentiate from the Moto's and Galaxy S that are looming on the horizon. Heck, that is just the three that are sure bets- there may be other high-end Android devices as well.