Why not have multiple feeds to allow for things like:
All tickets owned by myself in an open state sorted by priority.
All new unassigned tickets in a particular department sorted by priority/age.
Perhaps an RSS feed based on a search query would be the better way of handling this.
The only problem with this is security. By granting access to these feeds you would have to perform authentication from the application trying to get the feed itself. Not sure how feasible this is.
My 2cents anyway.