I remember the heady days of the late 90s (while the PCS build out was happening). Depending on how and when you counted, we had more than 6 mobile operators in the Boston area. Everyone was competing for customers, to the great benefit of the consumer, as mobile phones rapidly transitioned from expensive car phones to relatively low cost, widely adopted personal handheld devices.
In recent years we've seen that competition shrink to just four operators (Verizon, AT&T, Sprint and T-Mobile). At one time, I was hopeful that Clearwire would be one more operator, but then they became effectively joined to Sprint. More recently I've been hopeful about Lightsquared, although they are a long way from providing service.
Now we get bad news. AT&T is buying T-Mobile. Consolidation! Less competition not more. Ugh!