Yep, I dig that idea too!
The only thing at this point (beyond actually kickstarting this) is to avoid being overambitious from the onset. Since this could be, in my view, regarded as an open, friendly community event, we could think up some constraining mechanism or a set of rules designed to keep the scope of this thing within reach over a defined period of time - somewhat akin to what was tested during the last contest (no custom art assets or whatever). After the initial release/result is available, we could always gauge the amount of interest among participants for additional work aimed at improving/expanding the first version of the pack, you know, something along those lines.
Frankly, it may be better to aim for something that may seem slightly "limited" compared to what we believe we are technically capable of, and at least end up with something for the community to enjoy after a month or 6 weeks of work or so. Sometimes constraints can also stimulate one's imagination - it could be "a map must not exceed 5MB" and/or something else. You know