Well, you haven't really done anything :)
Old:
MyBusinessLayer _myBusinessLayer = new MyBusinessLayer();
var results = _myBusinessLayer.GetAll();
New:
MyBusinessLayer _myBusinessLayer = BL<MyBusinessLayer>.GenericBL;
...you just wrote it on one line.
Well, you haven't really done anything :)
Old:
MyBusinessLayer _myBusinessLayer = new MyBusinessLayer();
var results = _myBusinessLayer.GetAll();
New:
MyBusinessLayer _myBusinessLayer = BL<MyBusinessLayer>.GenericBL;
var results = _myBusinessLayer.GetAll();
...you just wrote it on one line.