By the same logic, the wikipedia: namespace shouldn't be part of the English wikipedia.
Each wikipedia will have its own wikipedia: namespace, in that language, for that wikipedia. The idea is to have a separate "meta" for discussion that concerns all the 'pedias, in English, as it is "the" Internet language (and Jimbo's American;)
The benefits to having it integrated are greater than having it separate.
Less maintenance, maybe.
I'm pretty sure the only real reason it hasn't been integrated is because it would be something of a pain to do.
Not at all. Adding yet another namespace is easier than having another script to maintain, even though it would share most stuff with the English Wikipedia one. It would take, say, 5 minutes to set it up and test a new namespace, and a script (or manual labor:) to move the contents.
But, the idea is to have a "neutral" discussion place for "where we go" etc., incidentially in English.
Magnus