I caught a bit of today's BBC's Working Lunch and they were on about this. IIRC according to their report the airlines would charge for the following for a second bag of 23kg (might have been 15kg for the first two)
Ryanair : £96.50
EasyJet : £54.50
BA : £60
I hadn't bothered reading the Baggage Allowance changes thread (until I used search) as I assumed it was only about the size changes introduced by BAA. I wasn't aware that from Oct. 11 BA will be charging (GBP60?) for a second bag on some flights.

Unbelievable!!