OK, so let's see... the current info we have says:
Boba Fett (Vintage Toy) = 3:12
Boba Fett (Black & White) = 3:12
Boba Fett (Holiday Special) = 2:12
Boba Fett (Droids) = 2:12
Boba Fett (Mcquarrie) = 1:12
Boba Fett (Mcquarrie/Johnston) = 1:12
Boba Fett (J-Slot Rocket Fett) = ?:96 {found in the Vintage Toy Fett box}
Boba Fett (L-Slot Rocket Prototype) = ?:96 {found in the Vintage Toy Fett box}
Boba Fett (Vintage Colors) = ?:96 {found in the Black & White Fett box}
So, if the case ratios that have been reported are accurate, it looks the three chases are being found in boxes for 3:12 ratio figures. That should mean that none of the figures end up short-shipped in a Master Case (ie no chases in a 1:12 box).
Now we just have to wait for the mega-sellers to start grinding out listings so we can confirm which are the 1:96 chases and which are the "easy" chases.