OK, maybe it's not something you can't live without, but I do think the puzzle unlock is quite an interesting and cool differentiation factor for the Samsung Fascinate. At least it makes a bigger difference than Motorola's different eye wallpapers for its Droid line-up. And let's be honest - a lot of people considered the phones just for their wallpapers, because they look so cool.
I believe the same thing will happen to Samsung Fascinate. Most people, even techies, care about impressing their friends with their own phones. I believe the "fit to unlock" feature is something they can impress their friends with. All you have to do to get this cool feature is get the Samsung Fascinate from Verizon.