I have a Synology NAS which supports DNLA. This is my networked source.
I have a Samsung TV (LN40C630) which supports DNLA. This is my networked viewer.
Any video/mp3/jpg on the NAS in the proper shared library location can be viewed on the TV (if the TV supports the file type/bit rate)
The Captivate can be used as a network source, a networked viewer, or as a go-between/controller. Therefore I can play music/video off my phone on the TV, music/video off the NAS on my phone, or use the phone as a remote control to play music/video off the NAS on my TV.
I have occasionally run into issues where the source is not compatible with the viewer. For example, certain music files can be played on my phone with the default player but not on the TV because the TV does not support the same bitrate or file type.