I'd really hate that. I love having closure when a series ends, not a 'leave it up in the air' ending to a great series.

"Fredo -- you're my older brother, and I love you. But don't ever take sides with anyone
against the Family again. Ever."

"My father taught me many things ... keep your friends close, but your enemies closer."

"I know it was you, Fredo. You broke my heart. You broke my heart."