Are yo saying your TV already supports DLNA? In which case find a Raspberry Pi or re-purpose another machine and install Linux on it and run minidlna. Or if your ~~PC~~ TV is not so smart then plug the Pi into it and run FlashSlideShow from the Pi.
Good luck!
Easy to configure and can run as a daemon: http://sourceforge.net/projects/minidlna/
http://stabbyjones.wordpress.com/2011/01/05/minidlna-the-best-streaming-software-hands-down/
I just found this program a couple weeks ago and now I don't know how I streamed without it. It even monitors the folders set up for changes. I don't know if there is an Ubuntu package but it only takes 2 minutes to compile.
But you didn't really answer the question. Do you want to play the sound output from the Pi to the DLNA speakers and use Max2Play to control everything, Or play the music files located on your pi's NAS to your DLNA speaker using your phone as a remote?
For the second solution, install miniDLNA on Max2Play, and you can probably use the okto software on your phone to control which songs to play.
I am less sure about the first solution, but take a look at something like this.
Do you mean "stream to" in the sense of "force itself onto another device" or "stream to" in the sense of "provide a repository of accessible media"?
I have not used this yet, but for the latter case, ReadyMedia/minidlna could/should work.
Alternatively, of course, XBMC/Raspbmc/OpenELEC, but that's a bit of an overkill if you want to do other stuff with it and just need the repository part.
Since you seem to know about Linux, rather than using PS3 Media Server like everyone here will suggest, if your media server runs Linux, MiniDLNA is much lighter weight and works perfectly.
Try this: http://sourceforge.net/projects/minidlna/
Very minimalistic so it can be installed on a very underpowered machine making a cheap media server. I run it from my linux laptop to stream to Sony Bravia DLNA TV. Works great without any issues but you have to re-encode the movies with mencoder.
It will work fine for serving files, which sounds like what you want to do and what that lifehacker article is about. Media server != playing video. It just means serving them over the network.
I've used minidlna in the past, but not for a PS3. I think there is also something called ps3mediaserver or something to that effect.
I have to recommend FreeBSD as a server OS, although it may be slightly tougher to use. I like it a lot since Linux is all about these ungodly command-line arguments to configure things lately (I'm looking at you, iptables and systemd). FreeBSD still uses simple text files for most things.