Swings vs Roundabouts
So it looks to me like you will be able to choose to buy certain things through the store or pay for "Premium" PSN access and get a bunch of that stuff included.
I haven't purchased a single custom theme or avatar, but all good if I got some included in a "Plus" package along with some games that I might be interested in (I have purchased a number of the "diversion/distraction" games distributed via PSN).
It will be interesting to see what the pricing is here in NZ.