My wife-to-be and I are spending 9 nights in Provence (Nice, Arles, Avignon, & Cassis) and 3 in Barcelona. What type of railpass (if any) should we get?
Probably none. Doesn't look like you are doing that much traveling. A decade ago it would have been a no brainer -- you got the pass. Now you really need to determine the point to point tickets and add it up. Also, you need to add to the pass price the seat reservation charge for trains requiring a seat reservation. And don't use RailEurope for price comparison.
I just returned May 09 and booked all my tickets from home or bought point to point tickets once there when traveling within the same country. I collected one set at the train station but all the others I was able to print out at home. It was definitely the way to go; much, much cheaper. Just remember when booking, your departure point is also the country you choose to go through the site. I booked/traveled from 4 different countries.