This feels pretty weird. It seems like a perfect case for a singleton, then you could set it to a new instance if you need to reset it. If you're not familiar with the pattern, Jon Skeet has a nice article here with implementations: http://csharpindepth.com/Articles/General/Singleton.aspx

Also, since you're using BindableCollections here, will there be anything bound to them that'll get weird if you reset it? Or should these even be bindable?