You can browse these in the Google news archive, or by using the timeline feature in Google news. Google are going to keep working on this, and they're going to serve contextual ads through the service. They say that they're also going to try and drive print subscriptions.
I can see this service being really useful for people researching history, as essentially it replaces the microfiche method at the library. It adds to Google's archived news data, and as we know, more data is always better. I'm not convinced I'll be using this service though, I'm not entirely sure what I'd use it for.