I luckily had a spare InvisibleShield for the iPad1 (don't ask why, I forget) - was digging around today and found it hidden somewhere. Anyway, I slightly modified the front cover of it and managed to cover most of the back, at least temporarily until I get the 'real' back covers.
If you're willing, I presume you would be able to do the same with those IS that BB's selling, albeit it's the wrong size, I don't want my new precious to have scratches ;-)
Edit: I just remembered. I ended up getting 1 speck of dust while installing the shield on my iPad...it was so annoying at first that I was more or less forced to buy another - I ended up getting used to seeing the imperfection and I guess I stashed it away and never returned it.