but the fact of the matter is like someone else already pointed out - there are *nix boxes all over the place that have some god forsaken version of irix or red hat linux 6.2
or some other dumb stuff that is just ripe for the picking
I don't have anything resembling your experience, and have seen some rather strange things - I don't doubt these exist, in fact I know they do. It just wouldn't be enough to selectively knock out deepbit as there are two servers on either side of the pond and, judging by the response times I get even with the huge amount of users deepbit has, they must both have respectable bandwidth resources themselves. IOW, you aren't just going to knock them off using TCP/UDP floods without causing serious problems for a whole lot of businesses, and that wouldn't be smart as there'd be a bigger outcry and the attacker would likely be found out.
windows has infinite security holes without a doubt but the fact is there are a lot more *nix boxes out there packing bandwidth than windows
Here's the point: a lot of bandwidth wouldn't do squat against a biggish target like deepbit. All you'd have to do to avoid the more pointed attacks is block some addresses and all the serious flooding attacks would draw too much attention.
You need something distributed that doesn't so much draw bandwidth as cause the server(s) to overload, and that is why you need the botnet. That way, Tycho can't distinguish the attack from friendly traffic before it gets processed by the server.
Frankly, I'm not even so worried about the DDOS itself as much as I worry that it might be the cover for a cracker who's trying to infiltrate the system. There's a lot of money in deepbit, so it's pretty attractive. Let's hope Tycho's countermeasures are successful...