Mic has released a new version of the DS emulator for windows called Dualis, heres whats new:
CPU: Modified the code for SWI 3-6 a bit
APU: Reduced sound latency. If this causes problems on slower computers you can enable a larger buffer in dualis.ini
APU: Corrected sound looping in most cases
APU: Improved resampling quality a bit (PCM8 only)
APU: Added a sampling rate option in the .ini file
MMU: Added support for the timer registers on the ARM7 side
MMU: Corrected mirroring at 0x3800000-0x3FFFFFF on the ARM9 when WRAM is split
GUI: Added a viewer for the ARM7 I/O registers
GUI: Added support for .ds.gba files (the 512-byte loader is skipped so they are effectively treated as .nds files)
GUI: Fixed problems with reading from the upper 32kB of ARM7 RAM in the disassembler