It solves another problem as well, like "I cannot go v6 to my servers because my load balancing and packet filtering black boxes don't do it yet".
For this you need an ALG. This could be something like Squid on a box with both v6 and v4 interfaces. Basically, we now have such fast servers available with such high-speed networking, that anybody can build whatever middle-box they need using Linux and BSD. Ten years or so ago this was not nearly so easy to do which is why vendors stepped in with their blackbox products. But today, the situation is different. If the vendors are lagging behind, cut them out of the equation. Eventually new vendors will step up to the plate and you may decide to replace your home-built boxes with something commercial at around the time IPv6 traffic growth goes exponential. Or maybe you will follow Google's example and stick with the commodity hardware and tweak your software package into a well-opiled machine.
In order to make use of 6to4, surely servers and load balancers still need to support IPv6 -- they just get loaded with addresses covered by a 6to4 prefix rather than a prefix assigned by an RIR or an IPv6 transit provider.
IPv6 transition has a lot more wrinkles than just choosing which one of the IETF transition mechanisms is your favorite. --Michael Dillon