The Publisher's Association is about to release the 2009 sales statistics today. I don't have the report yet, but according to the synopsis £150m worth of ebooks were sold in the UK in 2009, which was about double that of 2008 (£80m).
Total UK publisher sales in the digital sector stood at just over £150m for 2009 according to the soon to be released PA Statistics Yearbook 2009. This represents an increase of 20% from the previous year, which recorded £75m-£80m sales for 2008, following a 27% increase in digital sales recorded for 2007.
While the digital sector shows growth, it remains a small market, representing 4-5% of the combined physical and digital sales of UK publishers in 2009. Consumer titles represent less than 1% of sales whilst 13% of sales are attributed to academic/professional titles.