The Digital8 line was conceived to provide a path to digital for current owners of 8 mm or Hi8 camcorders. Unfortunately, the DCR-TRV140 can't play Hi8 and 8 mm footage, as its bigger brothers up the line, such as the DCR-TRV240, can. This makes it best suited to first-time camcorder users, who don't have archives of older formats that they need compatibility with.
In addition to the normal slew of ports (IEEE1394, S-Video, mini A/V) that have made their way onto the TRV140, there's also a USB port, which, with some included software, offers some interesting functions. Specifically, it allows you to use the camcorder to capture stills, or "broadcast live video with audio", when attached to your PC, according to Sony, which seems to indicate you can use the TRV140 as a WebCam.