I know that there are some plugins for this...
I was thinking about saving what is previewed... That is: when a user clicks “Preview” the textile is saved to
preview_drafts table with the URI path and user id. If something happens when a user comes to this URL again belowe textile area there will be link “Load from draft saved at Oct 1, 2011”.
This way drafts will get supported for textile areas...
When textile is saved (using this URI) a draft can be deleted (not sure how to implement this).