This was discussed on today's breakfast news link to BBC website. Bans are already in place at Blackpool Pleasure Beach, Blackpool Zoo and Camelot at Chorley, and others (including Alton Towers and Thorpe Park) are considering it.
I think it's a dreadful idea - these places are expensive enough already, and queuing for (often mediocre) food would just take another chunk out of the day. But if the big players start doing this, then I suppose everyone will follow suit.
What does anyone else think?