Well actually, its not that big of a change (relatively) , we have a material system, a scenegraph, etc ... those things are a fundamental part of every renderer. I can not put a timeframe on it since i have no experience with deferred renderers. The current renderer can handle a lot more than most people think it can. Racer has all the potential to look great, but there is not much content for Racer that can really show it off. All content comes from a community of hobbyists working on content in their spare time, which is amazing if you look at the amount of work that goes into making one track or car, but its hard to compete with other games that have a gigantic army of professional content-developpers working months on one little car.