I would imagine that being written in PHP is the main selling point for end users who don't have the knowledge to set up a Node.js based website.
Yes it is. You don't have to setup PHP. It comes preinstalled and preconfigured on most hosting products. You can copy Ospari and start to blog. No step and no configuration needed.
Also taking in the global context, most hosting plans that are payed in the specific country currency run on PHP without any configuration, just put your PHP files there and puff...magic, a website is running
Ghost is really beautiful. I created Ospari just because it is written in PHP and therefore it is easy to install.
Is going to provide all Ghost features or just will look like it?
It is too early to answer this question. The first version would have all basic features needed for blogging. Future features would be based feedback provided by our users.