Target (pronounced Tar-jay by those who swap Grey Poupon from their Rolls Royce) will continue to offer handsets from AT&T and Verizon, soon to be joined by Sprint. T-Mobile will be looking for another retailer to partner up with to sell its post-paid offerings. This could be announced before the end of this month.
If you have a Target credit card, you automatically get a 5% discount on purchases made at the store with the card. This means that if you are a T-Mobile customer with the retailer's card and want to take advantage of that discount on the purchase of a new phone, you have until April 7th to do so.