In my fork, the status "In progress" will be shortly going away. Those statuses will be merged into "open".
I know this might be inconvenient for some, but the initial move to customisable properties happened in January 2009. Now is the time to clear up some of the duplication left behind. If you rely on this distinction, please create a new task property called "status" (or whatever you like). For example, my statuses are:
investigate waiting for customer confirmed/approved testing documentation
My goal for the current status field is to make it more like "resolution". That is, the task is either 'unresolved' (open) or has one of a bunch of resolution states (which are already there). What exactly "wait until..." implies is something I'm thinking about, but is not part of this change.