The UK Kindle ebook store is now open for business. Amazon are also offering to transfer UK customer's Kindle store accounts from Amazon.com to Amazon.co.uk.
I've just done clicked the button to start this process. Hopefully it will be painless. The UK store has prices in £, not $.
Most prices seem to be a simple conversion from $ to £, with an exchange rate of about $1.55:£1. The current rate shown at xe.com is $1.58:£1, so it's not too bad at all.
It will be interesting to see how frequently Amazon update the UK price as the exchange rate changes.
Some UK prices are cheaper — as sometimes a cheaper paper version is available in the UK which isn't available in the US.
e.g. The Penguin Classics version of Kidnapped is $6.06 is the
US Kindle store (including the 17.5% VAT for UK customers) but is only £1.89 in the
UK Kindle store.
And no doubt some UK prices are higher.