Allwinner is a chip maker not a tablet maker, but right now, the Chinese company's products are a very popular choice for ~$100 Android devices, whether we're talking about cheap Android tablets or those sub-$100 pocket PCs based on ARM chips.
Allwinner chips usually have a 1-1.5 Ghz Cortex A8 CPU, coupled with a powerful Mali400 GPU (same as the one in the Galaxy S2), which enables even low-end tablets to smoothly run ICS and to play any type of HD content flawlessly.
Analysts expect that 40 million tablets will be shipped in China alone this year, and it seems Allwinner's chips will be in 60% of those tablets (or roughly 24 million). Allwinner achieved this excellent performance through a close cooperation with ARM, which enabled the IC maker to go from licensing ARM's designs to manufacturing System-on-a-Chips in only 7 months. The fact that Allwinner is using both the CPU and the GPU from ARM means that they are also getting quality drivers from ARM, which contributes to making the process quicker and more efficient.
This kind of integration will only get stronger with future chips from ARM, like Cortex A15, Cortex A7 (big.Little) and the Mali T6xx series GPUs, which will even share the same cache. Cache sharing will only be possible with ARM-designed CPUs and GPUs, which will put chip makers who are using all-ARM architectures (Allwinner, Samsung, etc.) at an advantage over those who aren't (Apple, Nvidia, Qualcomm, etc).
We probably won't see such integration until the end of the year, and most likely until next year, especially for other companies besides Samsung. But things will get interesting quickly when even low-end devices will be able to run on Cortex A15, Cortex A7 and Mali T604 chips, thus enabling the release of very fast devices even in the $100-$150 price range.