Focus on WordPress — not on WordPress hosting.
No need to introduce WordPress. It's a cornerstone of the web and one of the reasons for the popularity of PHP. It's a blogging engine as well as a CMS. It's hackable and extremely skinnable. It's not known for a very modern PHP. But hey, there is a huge community and clients really love it!
fortrabbit is an uncomplicated WordPress hosting solution. It unites modern PHP development paradigms with classic workflows - the sophistcated PHP developer.