One thing which has been very important when it comes to creating special end user experiences have been the ability to show something fullscreen, effectively hiding all the other content etc. Web developers want to be able to trigger this too..and now we can!
I've previously looked at updates to form fields, but I had not really spent a lot of time looking at validation. I spent some time on it this week and have come away pretty impressed. Here is the first in a series of blog entries planned on the topic.