I have just noticed on the FH main site you can buy FH3, the full version as a download from them direct. The price is a little more than amazon.co.uk are currently charging for the Boxed program, but it might be a handy option for people outside the UK. There is no option to buy a V2 to V3 upgrade as a download, so it looks like you still need to buy that via one of the main resellers.
See Family Historian Products Page for more information