Attn Luca and Scott
There are some things best avoided as going against community expectations. I would be happy to see flagged revisions deployed on the English Wikipedia but I'm well aware that there is a significant lobby against that of people who believe that it is important that your edit goes live immediately. And with the community somewhat burned by bad experiences with recent software changes now would be a bad time to suggest such a controversial change.
Saving drafts is potentially more doable. My preference for new articles is to start them in sandboxes, that way you are highly unlikely to get uninvited editors unless you are creating an attack page or committing copyright violation. For existing articles you can simply copy and paste your draft of a paragraph into your own sandbox, but this is not exactly intuitive for new editors. Leaving a tab open on your PC is not viable if you are at an editathon, especially if you are on a borrowed PC, but it works at home. My recommendation is to encourage people to save little and often, however that still leaves situations where people need to simply save a paragraph or two somewhere privately. One option would be to write a gadget that gave people the option to save work to sandbox. They could then highlight the bit they are working on, or even let mediawiki suggest the bit they are working on, and have the paragraph appended as a new section on their sandbox with an auto generated edit summary giving attribution. That would require development but would I think be uncontentious.
Better merging would also be uncontentious with the editing community, but has historically been opposed by the developers. There several suggestions on Bugzilla marooned as "won't fix" it may be that this is a communication problem and the developers have a good reason such as not having the source code, but at present it looks like they as programmers don't understand how difficult it is for non programmers to resolve an edit conflict.
I would love to see some sort of private draft space created for editors where only they can see stuff. This would require a software change and a cultural change. Space is now so cheap that we can afford to have tens of thousands of editors each have a few megabytes of private space that only they can see and which no one need check because no one has access. But the idea of unchecked space and free hosting is controversial to some, I suspect it would require the foundation to say what the cost of a gigabyte of extra userspace was and for WMF legal to green light the idea of not checking the contents of things that only the person who wrote them can see.
There is an element of tension between better merging and private drafts. Basically the more differences emerge between the draft and the main space copy the more difficult to merge them back, this is one of the reasons why some people don't think that flagged revisions or pending changes is suitable for rapidly changing articles. That's why my preference is to save little and often and privately store the sentence you want to add not your version of an article.
Regards
Jonathan Cardy
Yes, drafts visible only to the user are different. I was thinking of flagged revisions in reference to your idea that edits would first go live only after a set period of time. This is basically flagged revisions with a trivial extension that the flagged revision always be the latest revision that is at least X minutes old.
We could also allow a time
window (even 30 minutes) before edits went live after one is done
editing (using above Ajax mechanism to track when editor open),
experienced editors would not need to swoop in quite so fast on the work
of new users, and the whole editing atmosphere would be more relaxed
and welcoming.
I think the challenge with drafts visible only to the user is that they are very likely to have a conflict and have to merge changes if they wait too long between starting the draft and later committing it.