Although bug 739080 helps applications quickly answer the question of "am I on 3G?", I think it misses the mark somewhat.

Specifically, "802-11-wireless" is not exactly the same as "not metered".

While debugging bluetooth stuff the other day I noticed in a log that Android is sending us

  'vendor_encapsulated_options': <'ANDROID_METERED'>

among the option fields of its dhcp reply.

We should make available a better property than PrimaryConnectionType (possibly reverting the other before people start using it) that takes this field into account (and possibly similar fields used by other mobile OSes).

One minimal possibility would be to add a new connection type advertised through PrimaryConnectionType as something like "802-11-wireless-metered" but I'm not sure if this is the cleanest thing to do...