I've used TauDEM using the python code in Arc 10 for the past few months with LiDAR data. You can place the python scripts into the Arctoolbox just as you would with a tool or modelbuilder. I don't know if it has all the functionality of the complete TauDEM for 9.3. The help and explanations are either abbreviated or not there, but help can be found in the supporting documentation. I've primarily used it to take advantage of the parallel processing (very helpful with the larger LiDAR datasets) and the multiple flow direction capability of D-Infinity and haven't encountered issues thus far. The area I have been working on is too flat to realistically use the stream delineation techniques included in TauDEM. Some good resources on terrain-processing for stream flow analysis can be found in Wilson (2012) Geomorphology 137:107-121 or a flow-analysis book chapter from Tarboton and Baker 2008 found on the TauDEM website. Recent efforts of headwater stream modeling include Sofia et al. (2011) Hydrology and Earth System Sciences 15:1387-1402, Jaeger et al. (2007) Environmental Management 40:775-786, and Heine et al. (2004) Annals of the Association of American Geographers 94:477-490. Hope this helps, Jay