Q: FCPROX 10.1 update - Can Multiple Editors Work within the same Library?

No.

would have multiple editors in different Mac's editing with FCPRO7 the same project

No you didn't. Not the same project simultaneously. They could use the same media.

You can use the same media in FCPX as long as it's outside the library.

What Tom sez is true, multiple folk cannot/never have access(ed) the same media at once - however - this link complexifies that answer:

http://www.10dot1.co.uk/content/FCPXInASharedEnvironment_FINAL.pdf

  I have worked in post houses where one person would be color grading while another is laying in simple visual/sound effects. I have tried to get answers out of IT wizards how this was possible but I could never hope to try and explain it... which brings in the notion of off-line and on-line... maybe, I think?

So - where "outside the Library" - would the media have to be stored in order for multiple workstations to be able to access it? Any folder? Anywhere? Multiple folders?:

http://www.dothill.com/wp-content/uploads/2013/04/Post-Production-Solution-Guide -Apple-Xsan.pdf

  ??

  Since Final Cut Pro Server is no more the company below is trying to incorporate FXP X in a server invironment:

http://cantemo.com/fcpx.html

   This is a subject that has come up with several house I deal with. While I try to convine them not to switch to Avid or even Adobe, I am just not informed well enough about media management and fast SAS.

   I wish that someone would elaborate on how Final Cut Pro X can be orgaised and implemeented in this way.