We took the last Southbound cruise on Princess Sept 15 '08. It was wonderfull, however a bit chilly and somewhat rainy. Neither bothered us as we are from the Pacific Northwest, and you can always find warm spots to hang out onboard the ship. Not that I am a shopping nut, but the deals in the ports were awesome. Even the ships crew were getting off the ship and shopping in mass, plus all of the attactions and tours were almost totally empty being the end of the season.
We picked up the cruise for approx $550 which included tax/fuel surcharge.
Was an awesome experience, even though I have been to several cities in SE Alaska.