[css-grid] Are grid positions animatable?

Hi all,

Apologies if this has been asked before, but I'm wondering if the position
of items in a grid layout are intended to be animatable? The properties in
the spec do not specify one way or the other.

I ask because I contend that the ability to animate elements from one
layout position to another is an important use case, and one where the web
struggles to match the UI experiences provided by native apps. Right now
the only way to do this is through JS layout libraries [1] and impressive
hacks like Steve Sanderson's use of generated nth-child specific transforms
[2]. If grid positions were able to be transitioned, particularly for
automatically placed items, it would make it very easy to build lists and
grids that responded nicely to insertions, removals, reorderings, etc.

[1] http://isotope.metafizzy.co/
[2]
http://blog.stevensanderson.com/2013/03/15/animating-lists-with-css-3-transitions/

Thanks,
Jon