1) Type Converters to convert attributes from strings to real types 2) The options on Binding- one way, two way, etc 3) Element lifecycle events- HTML custom

1) Type Converters to convert attributes from strings to real types 2) The options on Binding- one way, two way, etc 3) Element lifecycle events- HTML custom elements are a small step, but still missing so many 4) Extensible layout model. 5) Control Templates- shadow DOM is an attempt to do this, but is sub-par. Particularly in how styles and events are handled.