Why wouldn't they have more than 4 GB of RAM? Current Android flagships are shipping with 6 GB of RAM, and 8 GB phones have been announced.

I'm not sure about the laptop-class performance requirement, you mean for light browsing and office tasks, they should be there already (even with the emulation penalty).

Edit: 8 GB phone announcement: http://bgr.com/2017/01/05/asus-zenfone-ar-release-date/