Depends what they're doing; a typical home router isn't usually CPU-bound AFAIK. IPv6 packets can be larger, but conversely that means fewer packets for the same amount of data. Organizations that embrace IPv6 can probably simplify their networking by using globally-routable addresses for all devices (coupled with appropriate security measures - NAT qua NAT was never a security feature but it did give you an obvious single point at which to place a firewall). But I fear many companies will simply reproduce the complexities of their existing IPv4 networks in IPv6, at least initially.