Maemo is an open platform and whether it's 5 or 6 doesn't make any difference on this. If someone comes with an alternative window manager that works and seduces end users, then fine. If you find disturbing having more than 3 widgets then have no more than 3 widgets and be fine with that. Maemo won't force you to have all desktops full of widgets.... ... but if by the day this comes to your hands you find out that navigagting across widgets in a same canvas actually saves plenty of time and clicks compared to clicking icons in order to open and close fullscreen apps... Then Maemo will havesomething for you as well.
Yes, if you want to have only a couple of items on the canvas, and limit it to only one page, there's nothing preventing you from doing that. I personally think of this a bit like what happens with Facebook profile pages. Some people like to keep them really clean, others (especially younger people) might like a really long page, this kind of "information overload". The framework is flexible enough to allow both.