Ah, I should have clarified that a bit more. In my example the ArrayCollection was acting as the database, so the "data" field I used would be the "recordID" for your case. To update your database you could send back a delimited, ordered list that you get by looping through the dataProvider, and use the recordID to update the row. An example might be:
<cfset numlist="4,2,1,3,5"> <!--- this is your list of the order from flex --->
<cfloop index="num" list="#numlist#">
UPDATE mytable SET order= #order# WHERE id = #num#
This code has not been tested, it's just an example off the top of my head(CF is not my forte).