PS3 homebrew dev Andreas Oman has updated Showtime PS3 Media Player 3.1.126 which includes real Plugin support!A  See the changelog below.

"Change log (v3.3.107):

PS3 Showtime Media Player Repack v3.3.107 Changelog:

glw/container: If the weight if a child is 0, don't include it at all in any calculations
Add a settings that controls how much of a video file that needs to be played before it's counted as played
glw: Add .shadow and .outline properties to text widgets
lastfm: Add some asserts
glw: Fix some bugs in glw_tex_flush_all() (mostly used when reinitializing universe)
glw: Make $clone property propagate thru loader widgets
Fix fallout from i10n in nvidia.c"

Source

Official Site