As announced on the 16th, the Kuttari line has made its way to America! Only the first wave (Pikachu, Raichu, Eevee, Vaporeon, Jolteon, and Flareon) are on the site as of now, but according to this quote from the announcement, we should expect to see more of them: Many more are on their way, so keep checking PokemonCenter.com for more Kuttari Cuties!
Each plush is being sold for $9.99. There are no pictures of the tags, so I cannot say for sure if/how they are different than the Japanese tags. Unfortunately, there is still no word concerning Pichu's kuttari fate.
edit: It seems they have already sold out. You may be able to get them if you search for kuttari in the search bar and add them to your cart that way.
edit 2: it appears that it was a glitch and everything should be fine now. Almost all of the kuttari appear when you click the banner on the homepage. However, a few of them (awake Vaporeon and Eevee, and sleeping Pikachu) don't appear. You have to search kuttari for those ones to appear as of now.
edit 3: finally, all kuttari appear when you click the kuttari banner on the homepage.