Light is only visible if it reflects off of a surface, so holographic projections without reflective surfaces just aren't within the realm of science.

Unless we have another Cave Johnson come along to reinvent science....

Dan, "never" is a really long time...

Javier,

To give credit where it's due, it wasn't "J Allard's" project, it was a project developed from two teams at Microsoft Research. J Allard's team spent some time seeing if the ideas there could be used in a future project.

If the research follows the usual path you'll see the ideas in other projects in the future from Microsoft and other companies - remember that many, perhaps most, of Microsoft Research projects are released under public licenses and the research itself is generally releases through technical trade journals and conferences.

For more, go to http://research.microsoft.com and check out the future.

Dan,
I'd suggest tracking down the older vision videos from, say, a decade ago. I think you'd be amazed at just how much became real. There is very little, if anything, shown here that's not doable in the 5-15 year timeframe. Probably sooner.

Too bad this will never be real.