I'd like it if every MMORPG had an offline free play mode. The only ones I know that do are the ones from the Phantasy Star series. I can't imagine that it would be worth it, but it would be nice to have, even for H&H. On the other hand, I learned from UO that when you enable people to choose whether to play in a PvP environment or not, the majority of those who aren't complete dicks choose the non-PvP option, which has a horrible impact on the average quality of those participating in the PvP version. So, maybe it's worthwhile to force peaceful players to cope with aggressive ones, just so that aggressive ones are also forced to cope with peaceful and moralistic players joining forces to kick their asses before they take over the world. Maybe.
On the other hand, if what Phinix was imagining wasn't merely an open-ended man-against nature sandbox game, but rather a game mode that would be filled by AI-controlled NPCs, then we can all laugh without mercy. Except for those of us who want robotic, AI-controlled replacements for our friends and family... Hmm.