To really learn about the changes in Angular 2.0 Core, I recommend you watch the video of the presentation:
Here are some things I noted:
There is still HTML templating, but some ng- attributes have gone away. The following examples were given:
<button (click)="doSomething()">Go</button> <input [value]="user.name">
I'm not sure what the difference is between the () and the  though.
Angular 2 will bind to properties of elements, not attributes. For example, a checkbox doesn't have a checked attribute. It does, however, have a checked property. Some properties are serializable into attributes, but not all. So it gives Angular more options if it binds to properties.
Angular 2.0 will drop a lot of things we're familiar with: controllers, directive definition objects, $scope, angular.module,...
The goals is to replace controllers with a component model (code that could be used in a non-Angular app too). Directives will be replaced with annotations, and $scope is no longer necessary now that the component is the execution context.
Angular 2.0 will no longer use jqLite. Instead, it will use the raw DOM, as this way of working has become much better since the haydays of Angular. The mentioning of this (dropping jqLite) produced quite some applause. Moving on.
A last thing worth mentioning is that instrumentation will be built into the framework. This will make it easier to analyze performance, see what's happening,...
There isn't really a lot of info on the details of all this, and there is some criticism on this approach. The future will tell if the decisions taken are the right decisions, and how easy Angular 1.x code will be portable to 2.0 code. But I suspect there will be possibility for community feedback in due time.