This is one of those things that I would never use however I think is great for the majority of people out there that I know that probably have not opened up their router's interface since setting it up (years ago). Pushed (forced) updates is a good thing in some cases.

An interesting thought is also what if Google starts making use of that 4gb by prepushing/caching sites that you visit daily down to the device for instantaneous retrieval.

Another interesting idea is that this probably comes with a nice UI for people to see their inbound/outbound traffic for a given timespan. My guess is a lot of people (ie non Y! news readers) don't configure their current routers for this. Once they start seeing an exact number, it will be interesting to see how it compares to their ISP if it is similar to Comcast and has caps and overage fees for metered cities.