Nikon’s rebates for June include a $100 instant saving on the Nikon D7000 and $200 off the D5100. This offer ends on June 30th, 2012.
Update: the complete list of Nikon rebates can be found here.
In the UK there is a new Nikon 1 V1 and J1 £50 cashback promotion valid till August 31st, 2012:
BestBuy seems to have Nikon D4 in stock: