We booked on Celeb Mille/Panama Canal, lvg FT Laud, 4/20/08 rtn SF..early last month. Have checked back about twice a week and price had gone up until yesterday 8/23 when price dropped $250 per person from original booking rate. We were in a CC cabin and our friends in Balcony 2A. The CC rate is now less $$ than their cabin which increased, so I bumped them up to a CC, larger cabin for less money. Can't quite see why this would happen and neither did booking agent but it does pay to check back, we saved $500.00.
Still have 5 months to go before final payment so I will keep checking back.