Both Linden Labs and Adobe recently opened the source code for products I've been exposed to, but haven't had much interest in until now.  Sharing the source for both Second Life and Flex has force me to reconsider them viable, long term technologies. 

Brian McMurray has been trying to convince me to use Flex on CakePHP in projects like phpLabMan.  I've been pushing back on these because I think they add a level of complexity on top of the LAMP stack that less people will be interested in installing or contributing to.  Whenever a company opens their technology to potential I feel like they are saying, we are capable of competing on a level playing field.  We offer services or interfaces that will add value to our version to the tools or environment.