I can't cite any specific articles off the top of my head, but I very distinctly recall the carriers vocalizing their concerns with how much money they were paying to Apple up front for contracts that take 2 years on average to close out. It makes perfect sense that they would experience anxiety over taking on another Apple product that sells by the millions. AT&T/Verizon may want to keep that money in their pocket instead of paying Apple to facilitate contract generation and then waiting to get paid back by the end users. Also, subsidizing a 3G/4G iPad wouldn't result in the same discounts as it does with the iPhone because we don't pay the carriers for minutes and text on the iPad, so how much money would really come off the top at that point? $300 at the most? Think about all the effort that the carriers would exert to make that happen, and for what? They still make their money either way, and without subsidizing the purchase they get their money more sooner than later.
Ultimately, my point is to still be careful what we wish for. The consumers and resellers would benefit very least from this if it happened in my opinion. You seem to think my opinion is wrong though based on your comment, so oh well. Other thoughts?
No, I don't necessarily believe your opinion is wrong. On the surface it definitely does look like it's a good thing for a consumer to get a contract if it saves them several hundred dollars on a device.
The fact is though, carriers love the contract-subsidy model. When a phone is sold on contract and a consumer given a $400-500 subsidy for signing a contract, the carrier doesn't necessarily lose $400-500 up front. Most of the time the hardware is highly inflated in price only to make the contract price look extremely appealing. And that includes iPhones. Last year for example, the iPhone 4 32GB went for $750 non-subsidized while a 32GB iPod touch 4th gen went for $300. Obviously the costs are a bit different between the two because of the cellular radio, camera, body, but enough to really warrant a 150% increase in price? Heck, even the new iPad 32GB with 4G is listed cheaper than the iPhone 4S 32GB.
The other thing is that carriers more than make up for the subsidy throughout the monthly payments during the contract. Tmobile for example has separate pricing when you bring your own device or don't take a subsidy, and it saves you $20/month on certain plans. In europe too (from what I've seen) the rate plan is nearly in direct correlation to the subsidy you received on the hardware. If you are paying only for service it can be quite inexpensive.
In my opinion, I'd love to see a full disconnect of mobile phones and contracts/subsidies from carriers. I'd much rather see good selection of hardware in retail, choose a device, and later pick a carrier. Similar to how Apple's been pushing the iPad. Choose service from any carrier and move as you need. Competition at retail between different manufacturers and the loss of inflated non-subsidized pricing will definitely help to drive prices down as well.