Hopefully not. I want one more run next year, regardless of how this season ends. It would be great if they retire as Celtics, together, and trying to lead some youngins to Boston's #19. And I think all 3 have 1-2 years of great basketball in their tanks. The only doubt is KG playing through pain, but he's KG.
An ideal situation would be a 2 year front-loaded contract for both KG and Ray, with a team option for 2nd year. I don't think there's any UFA out there worth the cap space, and if you have to overpay, you better overpay Ray and KG. At the summer of 2013, the big 3 could retire together and create cap space for some max free agent(s).
Celtic tradition was built with veteran stars retiring as Celtics and passing the torch to younger players. This would set a good example and probably would make the Celtics a better option for free agents.