Although clustered indexes are not required, and there are many cases where you should not use a clustered index, quite often clustered indexes can be overlooked when creating a table. This is actually more likely if you are inheriting a database from someone else who didn’t know enough about indexes. In these cases adding the right clustered index can dramatically increase performance on queries.
As part of the Database Health Reports, I have added the Unclustered Tables report to report on those tables in your database that do not have a clustered index on them. From that point you can analyze each of those tables and determine if it should be clustered.
Take a look give it a try. This report will be in Beta 2, which will be available for download on October 1st 2012.