[Earliest history of SL]

And Torley Linden also has a bunch of old SL videos on his Youtube channel (sorted by oldest first)
https://www.youtube.com/user/Torley/videos?flow=grid&view=0&sort=da

[Earliest history of SL]

Well, there's this one, which I was immensely amused by.

 

[There really should be an SL2. Not Sansar.]

41 minutes ago, ThorinII said:

I agree insofar that there should be an SL2.0 instead of Sansar. In my opinion, Sansar has been a dead birth, right from the start.

But it should be an SL2.0 with all the codes for servers and viewer written anew from scratch, without all the baggage on top of code written first about 15years ago; with a better viewer UI (= similar to V1.x, like the UI of Firestorm in Phoenix Mode); with an inworld mesh creating and optimizing tool; with better avatars, bigger regions and less region crossing troubles; and so on.

 

That almost reads like you would enjoy OpenSim. In OpenSim, you can have regions up to 1024x1024, build well above 4096 meters, the code is constantly being optimized and modernized, the scripting language is LSL but has Opensim extensions which (amongst others) allows for notecard creation, NPCs, customized windlight settings, and much more.
OpenSim is extensible, meaning that if you can code (.Net/Mono), you can add functionality to the simulator, like for example, in-world mesh creation. 
The avatars in Opensim are not very good, but there is an already popular project underway to create what they call Ruth 2.0 and Roth 2.0 which are open source Mesh bodies+heads and is currently in RC3.
Bakes on Mesh has already been successfully tested in OpenSim but is not yet publically available, because the devs want to try to keep it as close to the SL version as possible, and until SL has set loose BoM on the main grid, the devs will hold back the OpenSim implementation of BoM.
Viewer-wise, there is a project in its early stages to create a web-based client, a completely new standalone client, or both (I am not 100% sure which one it is).

So... as far as SL 2.0 goes, using OpenSim, you can do a lot to approach what you envision for SL 2.0 🙂

P.S. As much as I sing the praises of OpenSim, which you can quite easily run on your own PC, it's not all peaches. You start with... nothing and finding stuff to use in OpenSim can be challenging at times but can be done. I use OpenSim alongside SL because I can import textures, animations, mesh, and whatnot for free and experiment to my heart's content 😉