According to Wikipedia the first pictures in the UK were added in March 2009, with the remainder added in March 2010. So the pictures themselves were probably shot in the few months prior to that.
The veiw of our property is about two years old. Hate the idea of it though. We are very private, single storey property, with large high double gates. The image is taken above the gates and clearly show number plates on cars parked within the property grounds. Which normally wouldn't be visible from passers by.
Some people have had images removed, funerals have been imaged which have been very upsetting for the bereaved.
Where registration plates etc. have not been obscured you are meant to inform Google using the 'Report a problem' link in the StreetView window to enable them to remedy the situation.
We really laughed when we saw our house with a "ghostly hand" in the bedroom window - it was my husband just snapped by the google camera while he was gathering the curtain together to put in the tie-back!