For various reasons, a keyword in your campaign might be removed or declined.
How will you find out?
You will receive a notification email and/or you can have a look at your campaign alerts, visible on the "Dashboard" screen. You need to click "View all alerts" and then click on the one that informs you about the declined or removed keyword.
Where do you find the reason why it has been declined?
In the editorial status page you will only see the status, not the reason.
Just click on the keyword itself, you will then be directed to a very good explanation page with all details (which campaign and ad group, the reasons and suggested actions).

I assume this is just a feature in the new Panama?

Yes, this is a new feature in the Panama system. In the old interface we used to send our campaigns, creatives, keywords and negatives via an upload sheet. If any keywords were not accepted, Yahoo would have returned them to us as rejected listings.

Which version of the Yahoo Search Marketing Interface do you prefer?

One where a human reviews and returns your rejected listings after a 5 day delay.

Or - the automatic 'Panama' system which doesn't tell you which keywords have been rejected and you have to find them.

I prefer the new Panama version.
You are informed via an alert email and looking the keyword up in the interface as described above will take seconds and it actually quite exciting. It not just helps you to navigate in the system, you also feel more involved looking in the interface rather than just reading an excel sheet.

Plus of course, it helps increase the speed with which campaigns go live - so that has to be a positive for clients?

Agreed, the Yahoo old editorial lead time just delayed all ppc prcesses by 3 - 5 days, even if the editorial decision was unjust.

This usually meant all testing and tuning of the ppc campaigns would be led by Google Adwords.

Any further comments on the comparison between the two paid search systems?