In the long list of strange problems with 2.40 firmware...

Video playing from the network just stop working, I have used eyeconnect on my mac, for 3 months without any problem, but since the 2.40 firmware, it complains about a network problem each time playing a video.

That's why I'm trying a new (free) solution Mediatomb, an opensource DLNA server, for Unix/mac.

First intall macports and issue a sudo port install mediatomb in a terminal.

Start mediatomb a first time: /opt/local/bin/mediatomb wait two seconds then kill it with Control + C.

Edit the file config.xml file which is in your home in a subdir called .mediatomb (you can browse this dir with the finder just type open .mediatomb in terminal.

Change it to yes

<protocolInfo extend="no"/><!-- For PS3 support change to "yes" -->

Uncomment this line, remove <!-- and -->

      <!-- Uncomment the line below for PS3 divx support -->
      <!-- <map from="avi" to="video/divx"/> -->

After <import hidden-files="no">, paste this:

     <filesystem-charset>UTF-8-MAC</filesystem-charset>
     <metadata-charset>UTF-8-MAC</metadata-charset>

Run mediatomb, if you have multiple interface run /opt/local/bin/mediatomb -e en1 or just /opt/local/bin/mediatomb

Fire up your browser on the url given by mediatomb, in fact http://youlocalip:49153, browse and add the directories you want to share.

Don't forget to deactivate the web GUI, for security purpose.
<ui enabled="no"/> in config.xml or set a login password.

And the great news on the fly mkv conversion is working !! (tested with 720p mkv) to do that:
Create a file called /opt/local/bin/mediatomb-transcode-video:

#!/bin/bash

FFMPEG_PATH="/opt/local/bin/ffmpeg"
INPUT="$1"
OUTPUT="$2"
VIDEO_CODEC="mpeg2video"
VIDEO_BITRATE="4096k"
VIDEO_FRAMERATE="25"
AUDIO_CODEC="mp2"
AUDIO_BITRATE="192k"
AUDIO_SAMPLERATE="48000"
AUDIO_CHANNELS="2"
FORMAT="dvd"

exec "${FFMPEG_PATH}" -i "${INPUT}" -vcodec ${VIDEO_CODEC} -b ${VIDEO_BITRATE} \
-r ${VIDEO_FRAMERATE} -acodec ${AUDIO_CODEC} -ab ${AUDIO_BITRATE} -ar ${AUDIO_SAMPLERATE} \
-ac ${AUDIO_CHANNELS} -f ${FORMAT} - > "${OUTPUT}" 2>/dev/null

chmod a+x /opt/local/bin/mediatomb-transcode-video

Change <transcoding enabled="no"> to yes.

And add a transcode mapping : <transcode mimetype="video/x-matroska" using="video-common"/>

Add the profile video common:

              <profile name="video-common" enabled="yes" type="external">
                <mimetype>video/mpeg</mimetype>
                <accept-url>yes</accept-url>
                <first-resource>yes</first-resource>
                <accept-ogg-theora>yes</accept-ogg-theora>
                <agent command="/opt/local/bin/mediatomb-transcode-video" arguments="%in %out"/>
                <buffer size="10485760" chunk-size="262144" fill-size="524288"/>
              </profile>

and mkv map: <map from="mkv" to="video/x-matroska"/>

Your PS3 is now playing MKV.

Here is my config file: config.xml, don't forget to change the path for your home.

EDIT: thx prune for the comment, but you still remains a hobbit ;)