So luck apparently gives access to [Bloody Mess](http://fallout.wikia.com/wiki/Bloody_Mess_%28perk%29), [Grim reaper's Sprint](http://fallout.wikia.com/wiki/Grim_Reaper's_Sprint), [Mysterious Stranger](http://fallout.wikia.com/wiki/Mysterious_Stranger) and... leprechauns (possible wild wasteland analogue?).
Also still governs crit and loot.
It seems like Luck has some really solid combat perks associated with it this time around, when before it was more of a minor stat with some fun bonuses occasionally. Grim Reaper's Sprint in particular has always been a monster if you are a fan of VATS.