It will again be a quad-core system-on-a-chip (SoC), and the new Tegra 4 will sport four ARM-based Cortex-A15s as opposed to the four Cortex-A9s currently shipping in the Tegra 3 (although NVIDIA has dubbed its quad-core Tegra architecture 4-Plus-1 because there's a "hidden" fifth battery-friendly core for less-processor intensive tasks; the Tegra 4 will sport the same technology).
The roadmap, obtained by the Chinese version of VR-ZONE, points to a 10-inch tablet in Q1 2013, running a 1.8Ghz Tegra 4 (T40), with two more 10-inch tablets running 2.0 (T43) and 1.2 - 1.8Ghz (AP40) versions of the Tegra 4 in Q3 2013.
What's strange, though, is the SP3X chip also scheduled for Q3 2013 in a 7-inch tablet. That chip will sport the older A9 cores. That one, unlike the others, is listed as HSPA42 and LTE capable, though it seems strange that the other, more advanced SoCs wouldn't have that feature, too.
Perhaps there are just some missing details or something just got lost in the translation. We'll expect more details as NVIDIA opens up with its own releases.
The Tegra 4 is going to be slotted into both Windows 8 and Android tablets.
NVIDIA needs to improve the graphics capabilities of its Tegras, though. Although powerful from a processing standpoint, the Tegra 3 cannot compete with Apple's A5X (new iPad) or even A5 (iPad 2) from a graphics perspective, which is strange coming from a company known for its PC graphics offerings.