Warranty Inspectins or One Year Inspections are for newer homes whose builder's warranty is about to expire.  Getting a home inspection a month or so before your warranty expires can save you a lot of money.  There inspections are very important if you did not get a home inspection performed before you closed ont the home. 

Many significant defects can go unnoticed even by those living in the home.  Have you crawled to the back corners of your attic or crawlspace, or taken a ladder to get on top of the third floor ceiling?  If not, you can't be sure there aren't larg spaces of un-insulated ceilings or floors!  Have you used the shower in that extra guest room?  Have you tested all of the ground fault circuits?  Have you been on the roof?  If not, it is possible that the builder didn't either. 

Catching any defect now can save you a lot of money later.  I can't tell you how many times I have heard clients say, "that problem existed when I bought the house, and now I have to pay to fix it when I'm moving out!"