The two devices will be marketed under the "Sony Tablet" brand and will play nicely with Sony's premium services, including the PlayStation Network for gaming and the Qriocity media suite. In terms of hardware, both are powered by a Tegra 2 processor, offer wireless connectivity through Wi-Fi, 3G or 4G, and include an IR port for AV controls with Sony's line of Bravia televisions as well as other devices supporting the Digital Living Network Alliance standards.
As you'd expect, they'll run the tablet-specific Android 3.0 Honeycomb operating system and allow the use of PlayStation games -- with the S2 possibly using the bottom screen for gaming controls somewhat like the Nintendo DS.
The devices are slated for a global release in the fall of this year. Sony has said it aims to establish itself as the No. 2 tablet maker after Apple by 2012. It will face strong competition from the likes of Samsung, Motorola, Lenovo, Acer, Asus and numerous others, and it remains to be seen if the Japanese giant can be competitive on the pricing front.