I really don't know, like already stated, UFC has really been on the rise lately and they are probaly WWE's biggest competition.
What I think needs to happen for WWE to get huge again is get rid of the family friendly crap. Nobody wants to hear wrestlers run around talking about poopy or midgets running around getting kissed on the cheek by 12 year old girls and are obsesseds with candy.
Look at the attitude era, the WWE and all of their characters had an edge to them. I really can't remember one wrestler that was a cookie cutter goody goody face like we have now. All of the top faces had some type of edge to them (Austin, Rock, Foley, Jericho are examples) and all of the top heels were portrayed as evil sons of bitches (Triple H, Kurt Angle, Shane McMahon, Vince McMahon, MOD Undertaker, Kane are examples) that you could not wait to see get destroyed by the faces.
Today, most of the top faces are portrayed as goody goody, family friendly, smiley faces such as Cena, Big Show, Rey Mysterio and Kofi Kingston and a lot of the fans hate them because of that.
WWE needs more oomph to their product, they need to add more shock value and edge to their product in order to get people to care once again.