Whether I get a discless version depends on the price as well as how they handle backwards compatibility. Can I get a digital version of my disc-based PS4 games somehow? Great, I'm 100% on board with discless. No? Then I'm not so sure.
I doubt you'll get that option. Play Asia just had a listing of 700$... ouch. Not for me if that's true, even if they eat 80 off the cost to manufacture it'd be 600 for the discless. I hope this listing is just a troll and not Sony instructing to leak to test the water. This thing needs to be 499 max, disced and 449 digital. It's suicide if they go higher than that and it'll cause a stunned launch like with the ps3.
Only thing that gives me hope is that Microsoft essentially does it with all its backwards compatible games. But you do need to insert the disc the first time. Still, there are other ways to register your game online if Sony wanted to allow it.
Also, there is no way in hell Sony will charge 700 or even 600 for a discless console. I'd say best case scenario is 500 for disc based and 400 for discless. More likely though is 500 and 450. But if Sony wants to succeed, they will not charge 700. Play Asia has no inside info.