No matter what happens, it won't be overnight - HK will be slowly "naturalized" until she is indiscernable from her neighbor Shenzhen.
The good news is that Shenzhen is no longer just the destination for cheap massages, tailors and counterfeit goods. It's one of China's most prosperous and modern SEZ's -with all the new malls and residential buildings popping up, it really does feel like Hong Kong sometimes.
Meanwhile HK will slowly stagnate, as its traditional role as China's link to the West fades and it's status as a regional banking/financial services hub is lost to Singapore and Shanghai. Hong Kong does not want to integrate with the Mainland but it does not innovate to keep itself up to par with the rest of the world and unfortunately we will see the results of this soon enough.