The U.S. Department of Energy (DOE) has published a new report that documents early challenges and lessons learned in the development of the SSL market. Entitled Solid-State Lighting: Early Lessons Learned on the Way to Market, it summarizes early actions taken by DOE and others to avoid potential problems that were anticipated based on lessons learned from the market introduction of compact fluorescent lamps (CFLs). The report also identifies issues, challenges, and new lessons that have been learned in the early stages of SSL market introduction. The study identifies and characterizes 12 key lessons distilled from DOE's SSL Program results, with a focus on areas for which ongoing challenges exist and/or useful information can be applied going forward. These lessons correspond with technological challenges (related to performance and lifetime of LEDs, color quality and measurement, flicker, glare, dimming and control, and serviceability), challenges related to developing LED product lines and families, and complications and limitations experienced when trying to fit LEDs into existing lighting infrastructure. Thanks in part to lessons learned from CFLs, the development and market introduction of LEDs has gone much more smoothly than CFL market introduction. However, the unique technological characteristics of LED lighting have presented a host of new challenges and lessons. This early assessment of the LED general illumination market is intended to aid in the continuous course corrections needed to reach the technology's full potential.