4-6 week wait
Hi dervish,
I'm fairly sure you won't have to wait the full 4-6 weeks. Amazon tends to display this as a general rule when a book first comes out and they're not holding physical stock yet. Usually their system kicks into gear once a few orders have been made (and a demand has been proved). At that point they usually pull stock into their warehouse and show 'In Stock' with immediate despatch, so fingers crossed you get your book more quickly.
If not, Amazon aren't the only stockist and you can purchase the book elsewhere, including from the SilverWood Books secure online bookshop where it will be despatched same day.
Cheers,
Helen