Today I manged to upgrade a Yahoo Sponsored Search account to use the new Panama system. The upgrade was relatively painless, however, I discovered a few quirks in the system. The first thing that you should know is that the overall structure is now very much like Google AdWords, even sharing the same terminology (campaigns and adgroups) and it also has the dynamic keyword insertion tool which can be used in the ad title and description.
When you upgrade a campaign all of your existing categories will be converted into campaigns. Each campaign will then have a number of adgroups which will contain various sets of keywords. I only managed to spend about an hour with the new system, but I could not figure out if the adgroups came about because it was grouping specific keywords together or whether it had something to do with the ad copy. The answer may lie within the online documentation, but I didn’t have time to investigate.