I've come to realize, in these latest days, that the impact of namespaces introduction is much more than I expected to be. It's imperative that as many developers get involved in the discussion before an action is taken that may be regretted later.
Please start reviewing what has been going on the internals mailing list and what's already been added to the manual on the subject:
news.php.net/php.internals
php.net/manual/en/language.namespac
...
Also, if you can, please involve as many other developers as possible.
PS: I'll expose my point of view on these matters later, so that I do not bias your opinion with mine. Please get informed as much as you all can so we can discuss further.