That's it (as I understood it). The problem at [[Middle Earth]] does seem to be thy typing inconvenience. The proposal should solve it nicely and simple, without subpages.
I think Tims proposal is an excellent one, but if I'm honest it looks very much like subpages with a slightly different (better) notation.
But there are critical differences: most importantly, the article namespace remains semantically flat; "Foo (Bar)" is still a top- level article just like "Bar", and they have no pre-defined relationship of any kind, and no runtime features that link them in any way. People won't be tempted to use them to "categorize" pages into hierachies.
Secondly, since the easy-to-type form is replaced by the full form at save time, newbies won't even know about the shortcut and won't be tempted to use it, the way they were tempted to use subpages because they were /too/ easy. Only when one is experienced enough to recognize that this feature would be useful will you make the effort to discover it and use it.
Also, cutting and pasting from an article in one context into another won't change the links, which is a good thing. 0