I think there may be a misperception about some things. Russ, please correct me if I'm incorrect here, but...
EN World is a huge, recurring expense. So Russ did things to generate funds to pay for that expense. And then if there was anything left over, it went to him as a salary to pay for his life. What I think his announcement ultimately means is that he's going to get a "real world" job so that he no longer has to worry about scrambling to make EN World generate enough money to pay for his life. If it pays for itself, that's enough. The upside is that Russ gets to enjoy his hobby as a hobby and not as a business; the downside may be that we see him around less and perhaps he will have to make some decisions about the scope of the site.
So, now to your question about the "business side" of EN World. I don't want to speak for Russ, but as I understand it: other than handling banner ads (processing payments, getting them in the rotation, and that money going toward paying for the server), and handling community supporter donations (processing payments, providing the "thank you for donating" benefits, and that money going to pay for the server), there won't BE a buisness side to EN World any more. If such a time would come that the banners and community supporter accounts could not cover the cost of the server, then Russ will have to get inventive.
Your questions about EN Publishing, and what exactly Russ' role is in that business I cannot comment on as I have no knowledge.
Now, as a point of comparison ... The only way I could "afford" to run Eric Noah's Unofficial D&D News was that a) it was someone else's server and I was required to run their banners and b) I had a job and the site was just my hobby, so I could literally take it or leave it. The fact that Gamespy wanted more and more from me (they wanted 3 new kinds of ads besides banners -- popups, "boxillas" and "skyscraper" type ads) while providing less and less (remember how they'd just turn off my forums every couple of days during the busy times?) was one thing that led to my exit from running the site. I could never have done it on my own like Russ did, taking a gamble like that. I've seen how expensive running this site can be, and frankly I'm surprised Russ was able to make any money at all. It certainly can't have been hugely profitable.