The major change portej05 is referring to can have some more details explained HERE
But, to spare everybody, a quick rundown is thus: Instead of 66 *.sdr files for the shaders to encompass all the possible launcher combinations, there are now only 2.
main-f.sdr and main-v.sdr, which go in to data\effects.
Judicious use of #ifdef is done to handle how where and what handles who for how many cookies.
Best part? They can co-exist and with and will (with this build or Hery's topic posted build) override the regular MediaVP shaders.
Benefits can include, but are not limited to: instead of maintaining a long list of combo shaders that may or may not always play well with eachother, we can adjust the engine to use the main shaders as a default, or read an lookup file to be able to use scripting and/or SEXPs to change the shaders on the fly. The use of #ifdef means you can set FLAG types not necessarily used by the engine, and then call them.
Should make utilizing shaders in a TC much easier as well.