Actually there are eight new Lindt Creations: Four with deep-filled squares almost a la their filled liquer bars, and four with flatter-shaped filled squares, more akin to the manner which Double Milk is 'filled'.
The four deep-filled are Divine Hazlenut, Vanilla and Almond, Dark Orange and Luscious Caramel. I've seen all four in Tesco; certain Sainsburys also do some, though I'm not sure how many.
The Four flat-filled are Coconut, Creme Brulee, and Hazlenut Deluxe Milk and Dark versions. I've only seen these in Waitrose so far, though I bet Ocado do them too. Come to think of it, I don't recall seeing the dark version last time I went, so either they sold out at my store or god knows where I got it from.
The Four deep-filled seem much easier to aquire in 'everyday' supermarkets, though no one supermarket seems to carry the full range (typically, to increase revenue no doubt). I wish the flat-filled ones were more prolific, but then I remeber when I lived in Oxford there were Waitroses everywhere, so I suppose it depends where one lives.