Ultraportables of that kind aren't really new either, though.
I use a 2006-era ThinkPad X60 laptop every day. It's five years old, 76mm (25%) thicker but 90g (10%) lighter than the X1 you mention.
Although I admit the X1 has a significantly cheaper RRP, so there's one noteworthy difference - these things are moving from expensive niche objects to the mainstream. Apple arguably spearheaded the move there.
I use a 2006-era ThinkPad X60 laptop every day. It's five years old, 76mm (25%) thicker but 90g (10%) lighter than the X1 you mention.
Although I admit the X1 has a significantly cheaper RRP, so there's one noteworthy difference - these things are moving from expensive niche objects to the mainstream. Apple arguably spearheaded the move there.