Hey there. Just wanted to let the U.S. Whovians who are interested in Oswin's shoes know that you can get them at DSW too. Better yet, they come in a bigger range of sizes, US6 - US11. The style is called "Rock & Candy Sportier Wedges" but as far as I can see they're completely identical to the River Island shoes (including the tread pattern on the bottom of the soles, because yes, I am dorky enough to have checked). Thought this might be helpful for those who a) don't want to pay for shipping from the UK, and/or b) have bigger feet (like me!).
http://www.dsw.com/shoe/rock+.and.+candy+sportier+wedge+sneaker?prodId=259624 They don't come in half sizes, but my pair should arrive in about a week and if anyone wants to ask about fit I can let you know when they get here.
If you have a DSW account they have a free shipping promo right now, so I got mine for $65 total. Happy shopping!