It would probably save a lot of typing to just characterize Gwyn's Home as must-read, rather than individual entries. :)
Seriously, though, do read "OpenSimulator: the Choice for 2010". It's a comparison of the modular OpenSim design and the options that have been created for it with what we can infer about LL's server code from the glacial slowness with which changes occur and the way fixes to one bug seem to cause others, predicting that by 2010, OpenSim will be serious competition to LL. That discussion is combined with an honest assessment of the current state of OpenSim and the grids running it today.
A while back I quoted Fred Brooks's classic The Mythical Man-Month: "Plan to throw one away. You will anyhow. The only question is whether you will deliver the throwaway to your customers." Perhaps SL is the throwaway and OpenSim the way things will ultimately go. Gwyneth suggests in closing that LL adopt OpenSim and concentrate on adding value to it, and I hope they follow her suggestion.