-- Now what?The hit CW drama just aired its 100th episode tonight and while some fans may be scratching their heads after a few ultra meta moments, others are wondering what's to come for Archie, Betty, Jughead, Veronica and the rest of our favorite characters. To celebrate this milestone moment, ET recently called up star Cole Sprouse, who plays Jughead — aka 's forever narrator and writer -- to find out how much longer he thinks the series will last. Plus, we all know that this series has