Does anyone knows what he's talking about ? Dyson's sphere ? Surely there's some energy loss involved in the process ? But if it's true I'm happy to learn that an intelligent lifeform can theoretically live forever.
However for serious arguments sake, the whole problem in this question is "definition of life" itself. However even if we consider that heat death is inevitable and that we are assuming human beings to be around then. Then there are way bigger threats to our future than the heat death of the universe.
[1] http://en.wikipedia.org/wiki/Dyson%27s_eternal_intelligence
[2] "Time without end: Physics and biology in an open universe", Reviews of Modern Physics, Vol. 51, Issue 3 (July 1979), pp. 447-460
http://www.nybooks.com/articles/archives/2011/mar/10/how-we-...
"Gravitation reverses the usual relation between energy and temperature. In the domain of astronomy, when heat flows from hotter to cooler objects, the hot objects get hotter and the cool objects get cooler. As a result, temperature differences in the astronomical universe tend to increase rather than decrease as time goes on. There is no final state of uniform temperature, and there is no heat death. Gravitation gives us a universe hospitable to life. Information and order can continue to grow for billions of years in the future, as they have evidently grown in the past."
Unfortunately even if that is true, there is something called as entropy at play here.
Also I would advice you to read Isaac Asimov's "The last question" once. One thing discussed in that book is how quickly human kind or an intelligent being can grow in population and energy consumption.
So even before we reach the point of heat death, if we survive and move out to do the heavens. Then over time, we are likely to run out of resources and space eventually- may be even long before the heat death of the universe itself.