I would like slicers to flag each move with the type of that move (except where the type is the same as the previous move) as I described in my proposal for GCode that is less printer-dependent. See http://forums.reprap.org/read.php?1,803621,page=1.
I would really like this too. It just makes sense from a usability stand point - it also allows you to easily tweak settings in the machine while it's printing rather than having to stop reslice and restart. I would also like to see the filament files in firmware become more robust and have a UI that allows you to set any filament related parameters in the machine.
I know nobody really likes $tratasys but they are a good example to learn from. Their slicers only tell the machine trajectories and extrusion sizes, support trajectories, and some set up info like nozzle size (which limits the layer height and extrusion widths), as well as checking for special cases ie min layer time and special geometry, etc. Because so much of this work is offloaded for later, their slicing is much faster. You don't even have to tell it what material you are using (the machine takes care of this through the cartridge eeprom) although it can be input (I'm not sure how that affects the results). They have a couple hundred parameters in each of their material files which is specific to every material, model of machine, and nozzle size. The machines then use the on-board parameter files and the incoming information from the slicer to compile the actual moves the machine makes as the print runs.
