I'd hate to be in the Android hardware business.
The day will come when the manufacturers will barely be able to recoup their R&D, tooling and advertising costs for each model as longevity will be zippo and brutal competition will force prices down. See the PC manufacturing business for reference.
HP was smart to scoop up Palm - and they'll be even smarter if they focus on Palm-based hardware and not try to play the Android side too.
I'm pretty sure the Android HW manufacturers know exactly what they're doing when releasing so many phones so often. The mobile market is huge - measured in billions of devices. Neither Apple nor HTC nor Samsung etc could cater for it all. They can quite happily release a device, sell a few million, and while they're still selling those few millions release another device. This is how the mobile device world has always operated, and will continue to operate so long as there are hundreds of millions of buyers who replace their phones at fairly frequent intervals. I don't think the smartphone market is anywhere close to saturation at the moment, based on the small proportion of buyers who actually have one. Perfectly competent Android phones hitting the street for £50 (or less) free of contract (which is happening right now) will certainly absorb those users, and Apple quite rightly don't even try and compete in that sector.