Google has announced to the Early Adopter Program users that
We've not seen many user-facing updates to the Early Adopter version of Google Sites, in fact you can list them on one hand, here they are:
Here's an example of the differences in between Level and Impression
If there has been few updates to new Google Sites what can you expect? Here at Steegle we've been using new Google Sites for quite some time so we have a number of resources for you to see what is currently achievable with new Google Sites.
If you have any questions please let us know.