Well the problem is that as I understand it you need to get the FSD package right now to get the current advanced cruise control, which is kind of the party trick of a Tesla and a reason why I'd want one(that and the whole electric drive thing I guess).

And is the full self driving promise attached to the vehicle or the purchaser? In other words, if full self driving actually happens in 10 years, will the only people able to collect be original purchasers that still have that original car?

Seems like a great bet for Tesla either way. If they get to self driving soon, they'll make a mint and upgrading or even fully replacing those cars will be a drop in the bucket. If it takes them a decade, there probably won't be that many still around to make a claim.