Appearances deceive. In fact, with its PDAir case my N800 is bulkier than a Pandora (tested with a Pandora cardboard mockup and with careful measuring).
Since Pandora's price will be EUR 249.99 including (UK) VAT, I'd call it more than competitive. Don't forget that the Pandora has two full-size SD slots, two USB ports and a much faster processor than the N810. In fact, I'd almost call it a steal.