Programs. Love them or put up with them, elementary music teachers will likely be presenting some sort of a performance for parents. Some teachers, either due to their desire or what has taken place in the past, will put major emphasis on programs. Some drop their District or State curriculum and the music from the musical takes over. In many cases, the music is just a side issue. The major effort is put into choreography, costumes and sets.
Other teachers take what they normally teach anyway, and find a way to incorporate those songs and instrumental pieces into a program. In that case the curriculum stays intact. It's not my job to criticize any music teacher for their approach to programs. I'm just sharing a point of view that I'm hearing from many Orff Approach professional presenters.
Here's a podcast that explores that point of view:

http://orffsite.podomatic.com/entry/2010-02-06T18_01_25-08_00