Not to throw oil on the water, but it appears that even the French don't like to call their eBook readers a "liseuse". Bookeen calls the Opus a "
livre électronique". La Fnac's online store refers to the Sony 505 as a "
livre électronique eBook" and the Opus as the shorter "
livre électronique".
But of course if English speakers want to appropriate a French word for a different purpose, there's nothing to stop them.