The guy, in the video, below, isn't the best presenter, but he touches on some valid points.
Basically, he's talking about the oligopoly that the big four wireless carriers have in the US (AT&T, Sprint, Verizon, & T-Mobile). They dictate to the handset makers and service providers what content and features can be made available on their network.
It's referred to as the "iPhone hearings" because the iPhone, which uses a SIM card, is technically capable of working on any GSM network in the world, but AT&T has dictated to Apple that it must be locked to the AT&T network. This is a common practice, but, since the iPhone launch has received more attention than probably any other consumer electronic product, it's brought the issue front and center into the limelight.
Consumers - non-ATT customers - want this product but can't get it since they use T-Mobile, or some other wireless provider. This is similar to buying a Dell computer and being told that it will only work with Comcast high-speed broadband. Or, being told that a certain type and brand of TV will only work with NBC.
These issues are generally referred to as "network neutrality" and "right to attach".