Micromart, a UK-based console repair company, is ceasing its repair service for Microsoft XBOX 360 units suffering from the "3 Red Lights fault."
An update on their company page (http://www.micromartltd.co.uk/) claims that "(the) problem is endemic on the XBox 360 console and the volume has made this repair non-viable." They continue to support other XBOX 360 repairs.
Via their "Customer Info" page, Micromart suggests that customers with "3 Red Lights" errors contact Microsoft directly.
(Micromart Ltd has been providing a comprehensive repair service to Games Consoles for over 10 years.)