So, if you haven’t read Zak’s blog, you should, the guy has a lot of fantastic ideas. So fantastic that apparently WOTC decided to hire him to help with D&D Next, which is awesome. He wrote some posts a while back about how you could combine multiple D&D rule sets together that would make D&D Next work great. If the folks over an WOTC take his advice to heart, this could work out really well.
In addition he recently wrote an awesome post on a new way to handle called shots and other fancy attacks. Rather than simply taking negatives to hit, allow players to choose their critical range for the shot, and the shot succeeds within that range. The trade off is that for every increase in the critical range, the fumble range is also increased. So if you want your called shot to succeed on a 15 – 20, it will also fail on a 1-5. It is awesome, and I’m stealing it, with some modifications. The attack must still normally hit, so if you need a 15 to hit anyway, even if you extend your range to 13-20, you won’t succeed on a 13, though you won’t fumble either. Also you can only increase your range by half your level, round up.