I'm not laughing, and while I'm not an expert I don't really think of myself as a newb - I still don't know how to directly do what you're looking to do.

What I did was I changed the scripts that Advanced Interface Switcher uses (a program that replaces the default bluetooth status menu applet with a three-button applet, each of which toggles one of the following radios: bluetooth, wifi, and phone), so that they loaded and unloaded the injection drivers instead of the normal ones. That way right after a boot, the stock wifi driver gets loaded (but then I typically unload it until I need it with Adv. Int. Switcher anyway), and then from then on I get the injection-capable drivers loading.

A while ago I DID try to get the right drivers to load, by replacing some of the modules files in /etc/modules/current (which symlinks to /etc/modules/[current kernel name]/ - and editing some other files that near as I could tell told the kernel what modules to load and which modules depended on which other modules.

The result was a device that couldn't properly load or modprobe the driver in question.

Anyway, if you want to do it 'less neatly' you can probably make a script that's placed in /etc/event.d/ that will fire on, say, starting of hildon desktop, and will unload the stock wifi module and will load the injection capable ones. It's not as efficient as figuring out how to make them "truly" default, but it's transparent enough to you as the user, since you never see the stock driver in use. *Shrug*

In the meantime, I'm getting progressively braver with modifying the **** out of don't-touch-these-if-you're-not-willing-to-reflash files/areas on the N900, so if I can figure out how to load the new drivers completely by default, I'll probably post a thread about it or something.