Registered WXL users are kept up to date with free updates as and when they are ready, flibble! There is another one due this week in fact - thanks for reminding me. This latest one includes support for Natwest online banking, amongst other things.
I feel it is important to continue to provide free updates to browser users, because a browser's functionality is determined by pages created by the rest of the world. If you start charging lots of money for updates, you put people in a bad position - pay more money, or it's "game over" for the product they bought previously.