What a nice little suprise this was! You can now view your adsense account with good old British pounds. Read more here.
The option to change over to my local currency was presented as a special message on the first page. I am not sure where the option can be found otherwise. This is good news as I can now have a better idea of how much clicks are really worth to me.
Good work Google, note that this feature is being rolled out to other countries in the EU and you should be able to view your adsense earnings in Euros if that is your local currency.