Judging by community response, it's a nice piece of software with frequent updates. At the moment WAV/AIFF/AIFC/SoundFont 2 are supported + Typhoon compressed AIF files. More features below:
Unlimited multi-timbral operation
128 voice polyphony
16 modulation slots per voice
24dB resonant filter
Two LFO + Two modulation envelopes per voice
Built-in sample editor
Actually samples! Record straight into the sampler.
Graphical keyboard mapping editor
4 Stereo + 8 Mono outputs
16 mappable controllers for automation
Multiple loop definitions per wave
Individual outs for keyboard groups (drums)
Multiple keyboard scales
Multiple trigger modes
Preview loaded programs and samples in your song before loading
WAV/AIFF/AIFC/SoundFont 2 support
Reads Typhoon compressed AIF files
100% documented XML-based sound file format. Anyone can write conversion tools.
Low CPU usage
Fully native, optimized for SSE2.
Download: TX16Wx Software Sampler