Included are new features for the network stack, graphics drivers, Android code, storage support as well as basic architecture changes that enables ARM systems to address more than 3.8 TB of memory.
According to the published changelog, version 3.3 improves the handling of Intel's RC6 power saving mode, which enables Linux to reliably work with Sandy Bridge graphics units. The Nouveau driver package for Nvidia NVA3 (and up) GPUs now supports audio output via HDMI. AMD Evergreen GPUs now also support audio output via HDMI.
The developers have also invested some effort to "fight bufferbloat", which is a scenario of latency and throughput issues that are caused by excessive buffering. Byte queue limits are introduced to help solve the problem and enables developers to set a configurable limit of packet data. The Kernel 3.3 now also includes a NVMe driver, which acts as an interface for SSDs via PCI or PCIe.
Also noteworthy is the return of Android subsystem and feature code. The code was previously removed due to "disagreements". The kernel developers said that some subsystems and features are already available again and more will become available in the future.