yes, but for this to happen, both govt and IT companies needs to be proactive. We all know planning of indian govt, IT companies will not do anything for free. Besides, its myth that we have 'knowledge' from working in such projects which could be utilised in other places.
simple example is, if you are working in critical banking projects (say forex or currency market related), next time there is project in Retail Banking, the resource will be allocated to it. Its sear waste of knowledge/resource.
My personal experience: Was working in One technology, requirement came in Another, HR asked me to modify my CV for customer to replace Tech One to Tech Two and voila I was assigned to new project.