I suspected as much since the other geo-restricted books turned up yesterday and it fits with Apple's usual announcement timings. I'm sure they'll eventually get it fixed for the US store.
ETA: try this
link for the US store promotion and see if you can see anything. There's a selection of 8 and some of them are also available for Canada when I check.
ETA 2: Hee. Some of the once in the France store are free in Canada, too! I think I'm going to spend a lot of time checking for stuff tonight.