I have a problem executing the Mean Shift Segmentation in QGIS with Orfeo Toolbox. I put all the parameter to execute and then, nearly 5s after appear the message that SEXTANTE could not open the output layers.
What parameters did you try for the segmentation?
The OTB segmentation module got 2 modes, a raster mode which outputs a image of label and a vector mode which works on larger image and include a tilling scheme. This last mode output the segmentation results in vector mode.
Have a look to this post which describe the application:
Hope it helps