Interestingly, The Economist is among those urging the Obama administration to block the AT&T/T-Mobile merger:
The suspicion is that Mr Obama, desperate both to build some broken fences with big business and to make progress on connecting every American home to the internet, will give in. In fact he should push the FCC to promote more competition—by, for instance, allowing other firms to buy bulk wireless capacity from AT&T and resell it, by freeing up underused spectrum and by making local phone and cable firms share their wires. A duopoly would in the end reduce choice for American consumers, and be hard to reverse. Best to block it.
Meanwhile, just about everyone seems to agree that a huge underlying problem here is spectrum scarcity caused in part by so much of it being taken up by broadcast television operators who didn’t pay for it and can’t sell or lease it.