Currently, one can download the iso, or if one has two partitions, boot into
one and mount the other and untar sys.tbz2.  This is great.

However, if I want to replace a fully-partitioned system which is already 
running Linux with the tarball, I can't.  Well, I could, but there would be
cruft from the old install.

What would be neat is a script that could be run, and it would create a small
temporary bin dir with enough utilities within to cp sys.tbz2 into itself, 
then rm -rf what you have and pour sys.tbz2 into it.  Then remove itself.

Yes, if something goes wrong you are in a world of hurt, but it would be nice
to have as an option.  It's a feature I won't care about when rc4 comes out, 
but since I have scsi drives on one system and a k6 on the other, I haven't
been able to install Gentoo yet.  I think this could be useful for other
situations where it would be a nasty job to hack the .iso to include whatever
you need to get Gentoo running on your unique and problematic system, but
just adding something to the tarball would be a breeze.

Well, just a suggestion.

--Gabriel