Clove UK seems to have received the pricing for wireless charging accessories for Nokia Lumia 920/820 and are already taking order for these . But, they further add that at the moment they do not have a release date confirmed, but the accessories are expected to be available for the launch of the handsets.
Here is the price list,
Nokia Lumia 820 wireless charging shell – £16.66 (£19.99 inc. VAT) (26.68 USD)
Nokia Lumia 820/920 wireless charging plate – £48.83 (£54.99 inc. VAT) (78.2 USD)
Nokia Lumia 820/920 wireless charging stand – £58.32 (£69.99 inc. VAT) (93.40 USD)
Nokia Lumia 820/920 wireless charging pillow by Fatboy – £66.66 (£79.99 inc. VAT) (128 USD)
Nokia JBL Playup portable wireless speaker – £120.83 (£144.99 inc. VAT) (192 USD)
http://nokiapoweruser.com