I've wanted that for a while. Guess I should actually ask for it ... :-)
To mimic orthographic views, try setting your camera's Z-position and zoom to the same value, but really high, like 10,000. This begins to approach the orthographic "infinite zoom, infinite distance" concept.
Will it simulate an isometric view? Maybe if you parent the camera to a null (null is parent) and rotate the null, er, 30 degrees on X, 30 degrees on Y.