> The only feature removed > from Mame that I really miss is high-score support, but I really miss it. And yeah, I > know it isn't coming back.
One specific intent in including the Lua scripting language and giving it nearly unrestricted access to MAME innards is that high-score support could be added without ever touching actual MAME code and without creating an unnecessary derivative build. Someone just needs to make the script.
(There are other off-the-wall features that can be added through Lua too - I've already seen a hitbox viewer for certain fighting games, but I'd rather have one for shmups ;-)