Well geohot has made his NCK brute force tool public (he was the reliable source I referred to previously that has attempted the BF before).
You can download the toolkit from geohot site:
I just did and am looking into it, it would be nice if this thread would be for those of us attempting to look at the BF side of things and any useful comments.
PS! has anyone (including geohot) got a valid combination of the ltoken+norid+chipid+NCK+RSA message to validate that this indeed works e.g. if one gives the correct NCK that it spits out woohoo, key found