Unless anyone can come up with a creative way to use the supported repeating formats, I don't think it's possible to repeat like this, sorry. :(

This could work if there was a way to detect the present day of the week:
Search idea: presentDay:weekday
or presentDay:sunday
etc
I can think of many uses for this.
Emily: Any success in getting the developper to support "yesterday"?

Another way to fix this would be to create a giant search expression for each day of the week:
Smart list "monday":
due:"1 dec 2008" OR due:"8 dec 2008" OR due:"15 dec 2008" etc
preferrably created using MS Excel or similar.
If you create a list for each day of the weekends using this method you could use this in another smart list:
At work: list:work AND NOT list:weekend
should work, leaving out the repeats that are due on the weekends.
You would have to use repeating pattern "every 11 days" in order for the repeats to work, otherwise you won't get any new tasks.