Stemming from bipolar (namely bipolar depression), bipopular refers to the condition where a person may be loved and hated in relatively equal measure (or swing between the two extremes). Usually employed in regard to celebrities like Charlie Sheen, commentators like Bill O'Reilly, or musical artists like Kanye West, whose words or actions galvanise otherwise positive or neutral public opinion against them, and who have groups of followers and detractors, both of whom contribute to their fame.
Person1- "I love Lady Gaga!"
Person2- "I hate Lady Gaga."
Person 3- "Gaga's so bipopular!"