According to the latest leaked info, the HTC One S will actually be arriving at T-Mobile here in the US on April 25, which is three days later than we previously thought. This makes more sense, because T-Mobile typically likes to launch devices on Wednesdays, rather than Sundays.
Not much else is known at this point, although if we are to believe the leaked internal documents, T-Mobile expects to announce pricing and availability on April 16, although it won't be accepting any preorders. Additionally, we can expect a fancy new advertising campaign to begin on May 1.
These internal docs also tout some of the awesome features of this new device, including Beats Audio, Ice Cream Sandwich, Sense 4.0, and the awesome camera, but if you're reading this, you probably don't need to be reminded. T-Mobile also plans to sell a Solo Beats Headset for $199.99, along with up to 17 possible accessories, including the Media Link, cases, and Invisible Shields.