Believe it or not, Adam Sandler was originally supposed to play the part of Donny Donowitz (which later went to Eli Roth) in Inglourious Basterds, but had to refuse due to scheduling conflicts with Funny People. Another fact you might not know is that the two have been good buddies for decades, such that Tarantino actually had a cameo appearance, in make up no less, as the blind preacher in Sandler's Little Nicky. As a result, there's always a chance we could see Sandler show up again sometime, if Tarantino is willing to take the gamble that audiences won't be turned off by the much-maligned actor's presence. Still, Sandler has proven that he can act a) when he wants to and b) when he has a good script, and I imagine that both of those conditions would easily be fulfilled by QT. Sandler hasn't been in a good film in 5 years now (Funny People), so his career could certainly use the nudge.