Excellent comments, shared experiences and insights. Thanks to everyone.
While Regent may have offered "all inclusive" excursions to stimulate depressed sales in a down market to avoid a more substantial cruise price discounts, believe it is reasonable to assume they will recover these costs in their future cruise pricing as normal market demand for their product returns.
As a result, you will probably be paying for these excursions on future cruises (i.e. compare Regent per diem 2010 to 2009 cruise prices) whether you use them or not. When it comes to excursions, I prefer to pay for what I use as it gives me more control over deciding whether to use a standard cruise line excursion offering or to make my own arrangements. I don't want to be forced to pay twice when I decide (for whatever reason) to make my own arrangements.