Starting today, and running until next Monday 29th May, you will receive a 100% bonus when you transfer your Heathrow Rewards points into Heathrow shopping vouchers.
...Assuming that the transfer bonus also applies here, and I have been told it will, you would be getting 0.66p of Heathrow shopping voucher for every 1 Emirates Skywards mile you transfer. This is very good value for a non-flight redemption.