The Backpack Calendar has a default 6 week view with the current week at the top. The only way to see previous weeks is to expressly go back in time. Otherwise, you're always looking at this week + 5 more weeks ahead. http://backpackit.com/calendar
Google Calendar, too, has a very useful three week view which does the same thing.
Not enough for me. I would really appreciate being able to adjust the number of weeks (3-6) to show.
The view should show 1 week past and the rest future, regardless of the current time of month, and have continuous rather than chunked scrolling.