General/Core:
bug: fix a ton of old, broken cpu opcodes and CP15 logic
bug: return Z1 and Z2 from TSC (fixes some touch logic)
bug: gba slot save type detection improved
bug: handle unusual rom headers more correctly
bug: dont confuse motion pack commands with save memory commands
bug: make cheat system a little less flaky and add AR 1.54 support
bug: fix nondeterministic backup memory behaviour while rerecording
bug: correct emulation of register accesses of wrong size and during powerdown
bug: rewrite --cflash-path emulation
bug: rewrite IPC/GX FIFO, IRQ flag generation, and wait-for-IRQ logics
bug: rewrite RTC calendar handling; now supports years > 2038
enh: auto-DLDI patching for homebrew
enh: --gbaslot-rom=self mounts self.nds in slot2
enh: more realistic exception handling
enh: piano controller emulation
enh: modular slot-1 system for exact emulation of homebrew cards
Graphics:
bug: edge marking colors were wrong
bug: handle some "invalid" vram configurations correctly
bug: convert half of geometry engine to fixed point
bug: fix sprite blend+fadein/fadeout
bug: improve rasterizer shadows
bug: fix main memory display DMA
bug: fix some raster fx timing bugs
enh: add a hack for improving some non-stencil shadows
Windows:
bug: misc fixes and improvements to gpu viewer tools
bug: sub screen layer display toggling fixed
bug: fixes and improvements to ram watch, ram search, cheats list
bug: fix start-paused commandline
bug: fix memory leaks when sound disabled
bug: improve load average calculators and add arm7 load average
enh: background input support
enh: add vsync option
enh: support more knobs on joysticks
enh: import cheats from R4 database
enh: add xinput rumble for 360 pads
Linux/OSX:
bug: crash less in recent roms list
enh: Add horizontal screen layout and swap screen ability to gtk frontend (noodlebox)
enh: Big improvement to joystick support, support complex configurations and multiple devices (noodlebox)
Though there are no OSX build yet, pretty sure that won't be too much of the problem. ;)