Wifi and a distributable home web server
Webserver could be placed on a HDMI stick (not USB) and you could have game results showing on a big screen mounted up on the wall. Top ten scores per machine, top score per game in your collection...etc. You could then add in diagnostic features and on screen warning messages for games with issues. Pin inactivity with the TV still on would show random game pics and info.
Build on this to included head to head and top scores per game by world, region, country.s I know there will be cheaters but 80% - 20% rules shouldn't ruin your fun.
-Tourney software
-WIFI updates
If PPS and Stern open sourced their ROM's (stern could do it at the 5 year mark) a lot of games could be retrofitted to make this a reality. Alas, the big picture seems to elude both.