Quoting Daniel Friesen(Dantman)
Also remember that whether whatever settings for transwiki import you make, someone can always just use Special:Import using an XML file to import.
Upload import is disabled on WMF wikis (except en.wikiquote for unknown reasons :S )
But going along with that @... Yes, that is a nice addition which would make transwiki import a feature we could allow even non-admins to use.
It would be a nice feature, but I think allowing non-admins to use it would be a Bad Idea as lots of bad content would be imported inappropriately. Importing over top of a pre-existing page should perhaps return a request for confirmation like when moving over top of a page that exists.
However it would be good to allow a user to select a range of revisions. So if they really need an entire page, they can import the start, continue the import, and continue on. Bot frameworks like Pywikipedia could then easily turn this into a bot import task and slowly import an entire page without causing server load.
I'd rather see the import limit fixed. I forget exactly why it breaks, but I think it's either anything over a certain number of revisions, or a certain amount of data doesn't get imported (or, if you're lucky, gets imported partially). Some marginally better error messages were added for this, but it should work better.
There is an extra feature or two I would go for two. Title renaming primarily. Sometimes a Wiki has a completely different naming structure, and as a result you need to move a page after importing it. However, what if the wiki already has a page with the same name as the article on another wiki, but that article isn't the one that we want to import. So it would be nice to be able to specify a title to import to.
As an admin on a wiki affected in this way, I have to say that that feature would not be useful. This is what the Transwiki: namespace is for. Import by default to that namespace, and move to the new location; this leaves a redirect behind, which is almost always a good thing, since links on other projects will usually point to the Transwiki: page, and finding all links on all projects is really not that much fun.
Mike.lifeguard@enwikibooks