We currently have decent technology to insert foreign DNA into the genome of human cells (the newly developed CRISPR technology), so no need to turn to nanotechnology. However, understanding which genes allow the tardigrade genome allow it to survive extreme conditions and whether these traits could be transferred to other organisms with very different biology is not clear. Not all of biology is modular and can easily be transferred between organisms, especially properties that rely on the system-wide function of the organism.
Tardigrades are not the only organism to be revived after long periods of time, so there may be different ways of achieving such properties. For example, plants have grown from 30,000 year old seeds: http://www.nature.com/news/wild-flower-blooms-again-after-30-000-years-on-ice-1.10069