The classic example is Cricket Wireless, which marketed itself as a local calling substitute for landline voice service. Since many observers have noted that a 4G wireless service might be a substitute for a fixed broadband connection, one wonders when, and if, one or more providers will try and carve out a niche for 4G as a "wireline replacement" service.
Clearwire has been the best example of that, up to this point. Wireless likely will not be so workable a replacement for multi-person households and households that watch lots of online video. But 4G wireless might be a perfectly workable, or at least workable solution for single-person households, or households with unrelated persons, typically younger, who use about an average amount of data each month.
Some estimates peg "average" household consumption per month at about 12 gigabytes. But that is misleading. The "mean" or "average" includes consumption by very-heavy users who are a minority of all users. The "median" gives a better sense for "typical" usage.
According to Sandvine, for example, the median North American user consumed about 4 Gbytes on a fixed connection, monthly. If that remains roughly the case, then wireless is going to be workable for quite a number of users.
See the report here: http://www.sandvine.com/downloads/documents/2010%20Global%20Internet%20Phenomena%20Report.pdf
For further discussion about typical household consumption, see http://gorumors.com/crunchies/average-household-broadband-data-consumption/ and http://gigaom.com/2009/10/20/cisco-data-shows-heavy-broadband-users-are-early-adopters-not-hogs/ for more detail.