Peplink offers load balancing, redundancy with combo package: The firm is coupling its Surf 200BG wireless bridge, designed to connect to metro-scale Wi-Fi networks, and the Balance 30, a load-balancing network bridge that accepts broadband from both a wired connection and the Surf 200BG. If one connection goes down, the other is available. Requests can traverse either network, preferring the less-congested one, I'd imagine.

At $600, it's a bit pricey for a home user, but I can see where SMBs (small-to-medium-sized businesses) would find it a good investment. I've wondered about how many subscribers to a city-wide network would use that Wi-Fi service as both a backup (for inevitable wireline downtime, however brief) and as a mobile alternative. I suspect that some businesses will arrange special rates with retail ISPs to equip a number of roaming employees and have a link for their office. That Wi-Fi link could even be the primary one, with some metro-scale operators offering business-grade service at 3 Mbps or higher, and a lower-speed ADSL line acting as a backup.

An important factor for a multihomed bridge like this is that even though it can virtually bond two separate networks, it can't actually split traffic at the packet level. Connection-based services, like a VPN, would be routed over one of the two broadband networks and be disrupted were that network to drop. Web requests could be shuffled--one image request over one network, another over another--but it requires the cooperation of an ISP at the routing level to allow true bonded, multihomed networks.