I think the PG Era will last about another five years because by then several of the WWE's main eventers will be retired and the current midcard will become the ME. Also, you have to remember that WWE eras are cyclical and there will be somewhat of an Attitude Era revival somewhere down the line. The whole reasoning behind the concept of the PG Era was to coincide with Linda's political campaign and to draw in kids to the product. The PG Era has been succesful and profitable thus far because it's target audience is children and teenagers. A kid-friendly and family-friendly product is beneficial to the ratings, merchandise, and profit because the children bring their parents in to it to buy them the clothes, toys, dvds, tickets, etc. The end of the PG Era will be gradual with PPV's becoming TV-14 again leading up to the shows as well. As far as the WWE's policy on chairshots and blood goes, I think that they will not be as restricted in the future but they will occur just not on a regular basis like the Attitude Era. As far as long-term effects of the PG Era goes, I think that the audience will definitely have increased in the 7+ years that it will have lasted. I also think that the return of "edginess" to the product will really help heels get over.
Within the next five years I think that all of these main event or mid-card talent will have retired...
Kane, Rey Mysterio, Edge, The Undertaker, The Big Show, Chris Jericho, MVP, The Great Khali, Mark Henry, Goldust, William Regal
Obviously several lower card talents will be released in that timeframe as well
Lastly, I think that Triple H will either be retired and working in a managerial role or in a limited wrestling role
So to balance out the loss of so many WWE Superstars I predict these Superstars to rise to ME status if they haven't already...
Definitely the faces of the company will still be John Cena and Randy Orton but other prominent main eventers will be...
CM Punk, The Miz, John Morrison, Wade Barrett, Sheamus, Christian, Kofi Kingston, Alberto Del Rio, Daniel Bryan, Drew McIntyre, and Cody Rhodes,
while the upper midcard will include
R-Truth, Ted DiBiase, Jack Swagger, Dolph Ziggler, Evan Bourne, Justin Gabriel, Alex Riley, Michael McGillicuty (with a different name I hope), Kaval, Zack Ryder, Tyson Kidd, DH Smith, Tyler Black, and I think Mason Ryan from FCW will be a solid upper midcard-occasional ME player
These are just my opinions and predictions and I am really looking forward to what the rest of the IWC has to say.