The highly debate Butterworth (or Bagan Ajam) to Gurney Drive undersea tunnel, third link from Perai to Penang Island, may be a go project. It got support from Penang state opposition leader (BN - Teluk Air Tawar) Datuk Jahara Hamid. Yang di-Pertua Negri Tun Abdul Rahman Abbas did showed his support on the project in opening speech of Penang state assembly.
The proposed third link will be located near to Bagan Ajam. As expected, this will create big impact to the surround properties, example Sungai Puyu, Teluk Air Tawar, Raja Uda, Bagan Lallang, Sungai Dua, and may be to Kepala Batas and Bertam. The length of the connection estimated 6.5km. For comparison purpose, driving from Sungai Dua NSE exit to Tesco Seberang Jaya around 6km. Thus, driving from Taman Merbau Indah to Gurney Drive Penang will be estimated 12KM, nearer than drive to Juru Autocity (distant of 16km).
If you work in Penang FTZ, it might be a driving distant, from Gurney to Bayan Lepas. Anyway, the additional alternative road will give you option, and you got to try your luck to pick which path you want to take everyday.
This map show the exact location of the tunnel entrance and exit, it right beside the Taman Molek. As of now, rumors that the shoplots along Jalan Bagan Ajam had price increase and not much owners willing to let go, all would like to wait and see.
After all the good news on the Butterworth Penang tunnel, here come the bad news. If everything execute per plan, it will only start construction at 2019 / 2020 timeframe. And it need ~ 4 to 5 years to complete the construction. If you managed to show a house in this area, please keep it for another 10 years to see the boom. :)