Dave, 

Interesting start into Angular.  If I might let me make a couple of suggestions

1) In your update method explicitly test for the put method.  If anything but POST or PUT is gets into this method return an error.  This can avoid security holes in the future or inadvertent changes.  Having gone through a few penetration testing rounds and it can be surprising how and where holes can be exploited.

2) You might want to investigate NG Formly.  This is a great module that allows you to describe your forms in code much like we used to do with ZEN and provides a lot of features.

3) I am not really sure what you truly gain by creating all your own custom components for field types.  That is a question not a criticism.  I would caution on this however as you may end up in the same bind that ZEN was in.  Where you want to use a neat new component you found but have to wrap it or do extra work to incorporate it into your framework.  Going back to item 2 NG Formly, or some other similar toole, may help here.

Is this beta still open?  I heard the date was extended.

Daniel, 

Excellent article both from a historical and current perspective!

Rich