Having reduced the price by £10 to keep up with other shops, HMV are now offering a £20 gift card when you pre-order the 3DS instore. You can also trade your old DS for upto £110 trade in value (depending on which DS you have), you don't have to trade it in until you pick your new one up though so you won't be without one!! You also get a free HMV Pure (loyalty) card and double points which will give you enough points to claim another £10 voucher. You have to pre-order the 3Ds to get all this and I think you have to pay £10 deposit to guarantee one on release day, most stores are opening at midnight, my local store in Llandudno is.
*PRE ORDER* Nintendo 3DS Console & Get A Free £20 Voucher - £219.99 *Instore* @ HMV