Claudia Delena apparently quit the business because her young daughter found out she was actually in it. That's a big loss to her fans. I don't think she will ever return. Regarding Georgina Smith, I don't know why she quit - I hope she returns now as a much more mature woman. They certainly both had that 'it' factor.
Georgina Smith and Charlotte Birch (aka Claudia Delena aka Betina Blue), I would say the two classiest British porn actresses; I just haven't seen any actresses / performers of that quality since those two.