I'll be there too, with a girlfriend (Sheila), on both the 1/20/02 sailing and 2/3/02 sailing. Can't wait!!!
In terms of weather and what to pack, there is a good (albeit wordy) South American review on www.cruisereviews.com
. Click on destinations, then South American, then the Royal Princess review.
This couple did the Santiago to Rio parts of the cruise itinerary last January, and provide good information about what to pack, and what shore excursions they did.