3) Fix remaining rendering issues (offset-per-tile, range over, tile over, mosaic). Maybe we do just use the bsnes code - there's a fairly compelling story there, but are we willing to completely trash what we have?
It's Kale's and Fabio's code, not mine, but I would just like to offer my two cents: Having an emotional attachment to code in MAME or MESS is dangerous. Comparing MAME's code 10 years ago to MAME's code today, the drivers have almost nothing in common, and I don't dare imagine how much things will evolve in the coming 10 years. Speaking for the code that I've written, I welcome anyone to come in and rewrite it.