Sony is reportedly working on Xperia Tablet Z successor that will pack Qualcomm’s top of the line Snapdragon 800 processor. Snapdragon 800 processor packs quad-core architecture with Adreno 330 GPU and clock rate support up to 2.3GHz.

A forum member at Esato has revealed that this new Sony tablet will be released sometime in Q3/Q4, suggesting that we might see an announcement at IFA Trade fair.
There is no word on other details, but we can expect a 10-inch display and at least Android 4.2, it not Key Lime Pie, as the tablet is already indevelopment.
To remind you, Sony is going to release its Xperia Tablet Z in the Indian market in May, there is no word on the pricing, but we can expect INR 30-35,000.