Much of what I've seen/read about Lean Startups seems to be recasting of Lean Software Development and SCRUM/Agile techniques applied to the niche of "Startup".

Much of what I've seen/read about Lean Startups seems to be recasting of Lean Software Development and SCRUM/Agile techniques applied to the niche of "Startup". Much of those can be rooted in Lean techniques from Toyoda & others (Deming, Ford) applied to manufacturing from 60 years ago. Can you comment on why you think those (SCRUM/Agile/Lean SW) are different than Lean Startups? For example, if someone is practiced in SCRUM and is doing a startup - what do they have to gain from learning about Lean Startups?