A RhetNet SnapShot Reply:
Richard: Aside from your critical tone, I don't see much gap between what you're saying and what Beth is saying and doing in her snapshot. Without MBU-L there would be no snapshot? For true! And in more ways than one. Literally, of course, the words in the snapshot were slung together as part of a conversation. But putting them in this essay-ish form is not the contradiction you make it out to be.
You see, an essay, in its conventional form and purpose, is a statement. It isn't new to suggest that any given essay is an attempt by its writer to participate in a conversation with other writers. It's been OK to say that since much earlier this century when social construction ideas began to gain favor. But essays in the print tradition have been, nevertheless, primarily statements made by individuals addressing unseen and unknown audiences of readers who have limited opportunities to respond.
In spite of any resemblences you might detect, a snapshot (Beth's included) is not an essay in the same sense as a print essay. A snapshot is explicitly for provoking and continuing conversations with readers who quickly, if the snapshot is worth a poop, become writers. This may seem like a distinction so subtle as to appear wispy and frail, but snapshots are more essentially part of and dependent upon conversation than are essays. Essays are put Out There to be on display, to be read and admired and learned from. There is little chance to reply. Snapshots are put out there as bait. They actively lure readers into a conversational space where reply is not only more possible but tempting.
So you're right on when you say Beth's snapshot wouldn't be possible without the conversation from which it sprang. And it wouldn't exist without the conversation it provokes. It is interactionary or it is not.
When you say that the more interactive forms of writing we are so enamored of need not replace the essay, I would agree again. The essay will survive, but not untouched and unchanged. Snapshots, as a form, might be essays, as you suggest, but they are new breeds of essay. Hybrids, maybe. More dialogic, less dialectic. Still "polished prose" but not polished to a high shine for show, rather quickly buffed to accentuate effects. Snapshots may be what essays have to become to survive in cyberspace.