From our sister site MocoNews: Starting this fall, T-Mobile USA will take the extraordinary step of ditching its traditional deck on the phone and replacing it with a platform that’s open to almost any developer, multiple sources have told us. Think of *Apple’s* App store, but for the entire carrier’s handset line-up from smartphone to feature phone. As one developer, who was briefed on the matter, said: “The App store was a big deal, but that’s one phone. This is an entire carrier.” More here after the jump and full details on sister site on MocoNews.

In other words, we are talking about T-Mobile’s 31.5 million subscribers today vs. the 10 million iPhones Apple (NSDQ: AAPL) expects to sell by year-end (granted, the iPhone users tend to be more engaged as early adopters). The impact of this move by T-Mobile could set off a wave of changes in the industry, as other carriers feel pressure to offer new applications on their networks. Clearly, for this to happen, T-Mobile will have to follow through on its promises to encourage developers to participate. We are waiting for a statement from T-Mobile and will update when we have it....full details on MocoNews.

UPDATE: T-Mobile declined to comment on specifics, but issued a statement from Venetia Espinoza, T-Mobile’s director of Mobile Applications and Partner Programs, saying that people to stay tuned for more details in the coming weeks.