There are two new Enceladus-related papers in the May 17, 2007, issue of Nature: one by Nimmo et al. and one by Hurford et al. There is also an accompanying News and Views piece by Andrew Dombard. See the Editor's Summary for a synopsis and links.

Note: Those without access to Nature may wish to keep an eye on Nimmo's publication page. Reprints are often posted there.

Moon's Geysers Created by Ice Fractures
By Ker Than
Staff Writer, Space.com
posted: 16 May 2007
01:01 pm ET

Frictional heating explains plumes on Enceladus
University of California Santa Cruz
May 17, 2007

Cracks on Enceladus Open and Close Under Saturn's Pull
(Source: Goddard Space Flight Center)
May 16, 2007

PIA09209: Shear Heating on Enceladus

From the Stephens article:

"In the new paper, the researchers estimated the thickness of the ice shell to be at least 5 kilometers (3 miles) and probably several tens of kilometers or miles. They also estimated that the movement along the fault lines is about half a meter over the course of a tidal period." (BF & italics added by me).

Good grief...that's HUGE if those faults extend any depth into the shell!

There are two interesting related papers in the June 2007 issue of Icarus:

Tidal heating in Enceladus
Jennifer Meyer and Jack Wisdom
Icarus 188, 535-539 (2007)
Abstract
136 Kb PDF preprint

Enceladus: Present internal structure and differentiation by early and long-term radiogenic heating
Gerald Schubert, John D. Anderson, Bryan J. Travis and Jennifer Palguta
Icarus 188, 345-355 (2007)
Abstract

The Nimmo et al. paper and supplementary information is now available at the above link.

hmm, interesting papers. My only comment is that the predicted shear stress, which leads to variations in long-term heat flow, doesn't quite match the CIRS observations. In particular, it seems to predict that the anti-Saturnian ends of Cairo and Alexandria Sulci are coolest while CIRS shows this as a local maximum. The explanation for the temperatures observed however definitely seems plausible.