My simplified and contrived example is the following:-
Lets say that I want to measure and store the temperature (and other values) of all the worlds\' towns on a daily
I would use a single table with index views to provide me with the latest information. SQL 2005 and 2008 server are designed for data warehousing so should preform well under this condition.
If you have a data pattern that requires writing to the db often, then the best choice would be to have an active table and archive table that you batch update at some interval.