I find this Steve Molaro quote from this article http://tvline.com/2015/08/27/big-bang-theory-leonard-penny-married-season-9-premiere/ on why the TPTB decided it was time to let Penny and Leonard get married both interesting and somewhat promising for our favorite couple!. “We’re nine years in and we want to keep things moving forward, as well as exciting and scary and fun,” he says. “And I think this a great way to do it. Penny has had commitment issues for years and years now, especially when it comes to Leonard, and even she feels, ‘How much longer are we going to go back and forth on this? Let’s just jump in and hope for the best.'” I like the 'moving forward' line. Seems they believe that there is more story to tell of them as a married couple!