An actual Linux firmware replacement is still a long way off. For the time being Linux will be available as a dual-boot option enabling the average joe to run anything from quick-n-dirty ports of GP2X-linux titles or desktop linux titles to, eventually, some properly optimized emulators and, perhaps, original games and applications.
There's still a lot of hardware support to be implemented before it becomes a viable firmware replacement and, of course, a port of GMenu to make it actually usable.
The benefits of a linux firmware extend both to developers and end users. End users get a frequently updated and highly customizable firmware developed by people who, whilst they maintain an interest in developing for the Dingoo, are likely to listen to and implement suggestions. Developers get a familiar and straightforward environment that they can target... I'm extremely new to C++ but could muddle my way 'round porting and cross-compiling an app for the Dingoo, development for the normal firmware is probably not much more difficult, but is a total mystery to me.
Linux on the Dingoo is generally a good thing, it'll spur on more community development efforts and, even if it doesn't ever outright replace the stock firmware, it will bring a lot of applications that we would otherwise never have available.
It's also a good opportunity for people like you to dabble in being a "techie guy."