you may want to look into plex or even vlc remote.
i would read the plex forums carefully; I seem to be seeing folks pointing plex at roku streamers and ps3s via dlna configurations.
out of the box plex requires a plex server, so it would not work for me (I stream audio from a NAS) but if you use a computer as a dlna source, it might work and as i say, i am seeing what looks like folks pointing the client at streamers.
It costs 5 bucks though, so worth being sure it meets your needs.
You do not need a DLNA client to stream movies. If you run a home webserver it will stream movies. I have a ReadyNas drive that has a webserver and DLNA server built in. I use the DLNA server for my smart TVs but I use the webserver to stream movies to my Nook HD+. You need to convert the movies to mp4 faststart format. Faststart format simply puts the header info at the beginning of the movie. I use DVD Catalyst to do the conversion. Enable the mp4 streaming option under Tweaks. You can use the webserver on Vista or Windows 7/8. I think you need to enable WebDAV. Simply go to the webpage for example 192.168.1.200/media/movies/mp4. This is the directory with the movies. Tap the movie and it plays full screen. If you want to see this in action go to archive.org on the Nook HD like
Clike on the 512Kb MPEG4 format.