There have been a lot of changes in the roofing industry since the first of the year. GAF (Timberline Shingles) was the first to announced that all of their dimensional/laminate shingles now carry a lifetime warranty. Since then most of the other MFG's have followed suite to match the coverage set forth by GAF. Sounds great, and to a degree it is, but most people do not understand what the warranty coverage actually is. Simply stated, the shingle MFG WARRANTS their product to be free of MFG defects. They DO NOT GUARANTEE that the materials will preform to any standard other than wind rating, defects, algae resistance, etc. Most homeowners think that if they buy a 25-30-40-50 year shingle they will never have to worry about replacing that roof in their lifetime. Ventilation, underlayment, proper nail placement, proper flashings, use of starter strips and capping will all play a factor in how the roof system preforms. Shingles are not guaranteed to preform, except for the workmanship warranty that your contractor provides. When you are in the market for a new roof don't be as concerned about lifetime rating, but pay more attention to weight of asphalt per square and wind rating. Some MFG's make up weight by overappling stone granules to the back side of the shingle. Granules are a UV protector and serve no purpose except for color and UV protection. Granules are cheaper than asphalt. The supply houses in my area have already announced a 8-10% price increase effective the first of March and if we have a major tropical storm, we will see a series of price increases. Asphalt demand and inflation looks to cause a spike in material cost this year. We use a lot of copper in roof installations and right now copper is trading at an all time high and we have recieved word nails and all metals are also going up soon. If you are thinking about putting a new roof on your house this year, I'd suggest moving forward as soon as you are able.