It looks fantastic (to coin a phrase from a Doctor not featured in this book). As nice as the cover looks on a JPEG, it's as nothing to how gorgeous it is on an actual hardcover book.
The book's available in UK bookstores, as well as through Big Finish, Amazon.co.uk, Who North America, and the wonderful folks at Mike's Comics. It's also possible that the Forbidden Planet in New York will be carrying it, as other Short Trips have been sighted on their shelves in the past.
In addition, I'll have copies for sale at Shore Leave 30 in July for the low low price of $20, with the added bonus of me and nine of the twelve authors being in attendance at the con. *grin*