Motorola has apparently realized that the Milestone/Droid is also popular because of its full keyboard: with the Devour comes another device that offers a complete keypad - and looks even better. In addition, the Motoblur interface for Android is used, which displays status updates from social networks like Facebook directly on the home screen.
The display is a bit smaller, and the Devour is currently only available from Verizon in the USA - and is therefore incompatible with European GSM and UMTS networks. If the Devour is successful in the USA, however, Motorola is not likely to miss out on the European cake.
Technical details and a 360° panoramic view are available on the Motorola website about the Devour.
I rather think that the Milestone is "only" popular because of its keyboard. HTC and Motorola are kind of sharing the market. If you want a keyboard, you go to Motorola and if you want a virtual keyboard, you go to HTC. All other manufacturers somehow fall by the wayside.
However, your statement is only to be considered on the Android market or do I understand something else wrong?
In the android market I would fully agree with you. HTC is in the lead at the moment, after that comes Motorola if necessary.
But if you look at all the phones with a full keyboard, there are other phones than the Motorolas, simply because they are more stable and have different software.
Meanwhile it has become difficult to compare many mobile phones, because the operating system is always different (unless they all have Android) and therefore you can't take a decisive comparison factor into account^^.