Well, I've been thinking about altering 3e's crit system. I'm pretty sure that I'd like to sub in Hackmaster's system for the standard one. I've got a pretty good idea of how I want to handle it, but there are a few issues that I'm not sure about yet.
For those not familiar with HM's system...
Pretty good, I think. If played well, it could go over. Might have to make sure the rich villain isn't too over the top depending on how your campaign is run, but nice :)