An official deal is a long ways off, but it is possible and was in the plans of Sprint for a duration of time. Possibly a bid of $20 billion, but there aren’t any solid numbers to go by. The crux of the matter is that Sprint wants to buy out T-Mobile, which when observed from a technical standpoint already poses many issues, such as the fact that Sprint uses CDMA technology and T-Mobile uses GSM, making existing towers and phones incompatible with each other. And that is all besides the FCC approving or declining the deal.
But if it does work, then the big four become the big three, and Sprint has network coverage, capital, and users to rival the forces of AT&T and Verizon Wireless.