Nike have made a limited edition set of 1500 pairs of the shoes for which they are auctioning off 150 pairs at a time over at ebay.com (the current set are at over $8,000 already) and the net proceeds are going to The Michael J. Fox Foundation, Fox being the star of Back to the Future and suffers from the condition himself.
There are a number of videos that have been produced to promote the shoes and the auctions which I have posted below. The auction is only available in America, but if you are lucky enough to live there, or indeed be visiting then this is a great chance to own a bit of the future, and 4 years early.
(Please note that these shoes do not actually self tie!)