Which Groupset?

105 will go electronic, I reckon, for the price of mechanical Ultegra, once the economies of scale kick when they're selling a lot of Di2. Tiagra: no. At least, not for the foreseeable future. 105 is still pitched a little above commuter spec, which is the Alfine/Nexus market.

What I can definitely said that Tiagra will have the same body style as the 105 et all, especially after Sora have now got the old Tiagra body (which IMHO is an improvement over the original Sora despite not feeling as nice as Tiagra)