yup... the block is what allows it to fit in the lower. and it is a pattened block... so if I'm seeing this right they arent really selling AR15's they are selling a new type of AR platform rifle (AR10 maybe???) and Colt conversion blocks. But they are marketing as a convertible AR15. I haven't been listening for it but I wonder if they are acutally calling it a AR15 rifle. They could probaly lead to it all day and never actually say it.

But the iPod was an MP3 player for sure. You just had to have iTunes to use it... Companies always trying to push new proprietary formats as open systems.

I still like the idea of the rifle though... just recognize that Colt is in line to sell more block than rifles and uppers if it takes off. since it appears that the block is actually attached to the uppers....