Don't expect any unlimited 4G pricing, those days are gone forever when the older contracts end.
I don't know if LTE at full bore is quite fast enough, but doesn't it stand to reason the next gen (5G?) will be fast enough that they'll invest to add capacity to provide home broadband and ditch the expensive fibre optics?
At 5-12MBps it seems like LTE could be a viable home broadband alternative, IF they have the capacity. For, say, $80 a month they could give you an air card for your PC and include unlimited data for the phone. Just looking at their latest pricing plans, $80 gets you 10gigs/month on mobile pc access. That seems pretty steep to me and I'm not sure if 10gigs is enough for broadband replacement or not.