Google's US Patent Application
#20050071741 - Information Retrieval Based on Historical Data supports the conclusion that longer term registrations are conducive to higher SERP.
Per analysis of said patent, at
SEOmoz | Google's Patent - Information Retrieval Based on Historical Data ,
Domain-Related Information
Information associated with a domain can be used by Google to score sites in the rankings. They mention specific types of " information relating to how a document is hosted within a computer network (e.g., the Internet, an intranet, etc.)" including:
- Doorway and "throwaway" domains - Google says they will use "information regarding the legitimacy of the domains"
- Valuable domains, according to Google, "are often paid for several years in advance", while the throwaway domains "rarely are used for more than a year."