Grant/Gail, It's very very good article and rather very great thing provided by MS. However as it mentions:

"The downside is that updating the statistics results in recompilation of the queries accessing the table. This again can increase the risk of getting a different query plan for the next executions of queries against those tables. On the other side, the dynamic threshold to trigger update statistics should address issues encountered like not finding a new month or new fiscal year for month end reporting in the statistics and hence choosing a sub-optimal plan."

Don't you think once the statistics are upgraded, even if the new query plan is created, it will be optimal ?

And secondly, what does it mean by the issues like "not finding a new month or new fiscal year for month end reporting in the statistics and hence choosing a sub-optimal plan" ?