As I understand it, no one will have CSS customization.
I refer you to this for any further questions, as I feel I shouldn't expand upon this.
http://www.myspace.com/pressroom?url=/comp...ew-profiles.htmQUOTE
In keeping with our mission to highlight talent, future iterations will allow users to submit their digital art for the theme gallery. This new take on self-expression through design will incorporate a new robust theme machine, enhancing the ability for partners and users to create specialized profile designs for musicians, celebrities, brands and anyone else who wants a unique design. Additionally, we are working with design firms to build tools that allow third party sites to display and promote themes, and support the ability to designate a theme for one or more profiles without submitting it to the theme gallery.