Yep, there's a reason we have the industry term "humanization" in sound design, composition and arrangement.
replyTons of work has been done on various modes of humanization by trying to parameterize and modulate these aspects over time. Timing accuracy, velocity variance, chance, etc.
A well-played instrument certainly feels like someone speaking and expressing themselves to you. There are attempts to capture this with MPE instruments such as the Osmose, or Imogen Heap's MiMU gloves.