Today Apple posted a short white paper "Final Cut Pro X: Xsan Best Practices."
KB article: http://support.apple.com/kb/HT5084
White paper: http://images.apple.com/finalcutpro/docs/Final_Cut_Pro_X_Xsan_Best_Practices.pdf
Excerpt from the intro:
This document is designed to help you determine the best way of working with a SAN, such as Xsan, to speed up creative work and eliminate copying files across networks or hand-carrying hard drives on multiuser projects.
Two common scenarios are described below.
The first scenario sets up Final Cut Pro X for multiple users who will share a single project and Event, with editing access limited to one user at a time. This is essentially a “check-in/check out” workflow—for example, two editors on day and night shifts, or an offline editor who hands off the rough cut to another editor in a finishing suite.
The second scenario sets up Final Cut Pro X for two workstations sharing the same media simultaneously. For example, one workstation might act as the media-importing station and as a secondary edit station. The other workstation might be used for editing only. In this scenario, both workstations can access and edit the same original imported media stored on the SAN volume.
As far as I can tell, this is just a description of how best to use the Xsan support added in 10.0.1. I don't see that 10.0.2 or 10.0.3 have any special features that are leveraged here.
The Xsan support described is pretty simple and not very different from that of Final Cut Pro 7 and prior versions.
Basically, Final Cut Pro X relies on an Event database that it must have exclusive write access to. It is located in a folder, usually with its related media, and can reside anywhere on the SAN (not just in a root folder) as long as it's not nested within another Event folder.
Solution 1, sharing a single project and Event, is done by using and writing the event and project to a single folder location on Xsan (initiated by the File menu command "Add SAN Location"). When one editor uses the File menu "Remove SAN Location" command, or quits FCP X, the project is closed, and the Event database is released and made available to another editor to open and have exclusive write access to. So there will be just one project file, which can be used by only one editor at a time.
Solution 2, sharing media, is done by each editor having their own event folder (with its own event database) on Xsan. The second editor will point at media in the first editor's folder, but will use the media by reference instead of by copying it to their own event folder. Each editor will have their own project file.
In a nutshell, the white paper makes it clear how to enable the limited functionality available. Unfortunately, what is telling is what is not addressed:
So it's nice to see this documented, but unfortunately there do not seem to be any magical new capabilities for advanced sharing capabilities revealed. Time to get those feature requests in!