More and more analysts are agreeing on a late 2020 launch, which is quite sensible and likely. About specs, I still think there will be more than just one SKU at launch, at least an entry level and a premium one (that won't be a Pro one yet, that will come years later) and there could be a third SKU too, a hybrid, if Sony will decide that Ninty's idea can work well for its market too. Anyhow, a hybrid could come later, if the minimum necessary CPU power won't be available at all or at the right price yet on mobile CPUs when the home versions will launch, even if the undocked hybrid will run not only with lower graphics settings, but also switching off any non strictly necessary service.