Your most important web content management use case is also probably the simplest.  Yet it's easy for us to get excited about all the possibilities (in other words, the complexities) of a CMS and lose focus on this important use case: your day-in and day-out publishing process. 

Sure, in the back end you may have a million moving pieces, but the point is that your content publishers must have an easy time publishing workaday content.  Failing that, you risk many problems in a CMS implementation, like CMS user revolt (or at least high agitation), inconsistent content (by non-standard workarounds being used), and an unsustainable system (by concentrating too much on the one-offs).

Before diving into this more, note that concentrating on the simple use case is important for even the most complex implementations.  This isn't just a small site issue.  In fact, small sites can probably get along fine with a clunky publishing process.

Assuming you are following the Real Story Group's suggested approach for selecting a CMS by evaluating against use cases, some of the characteristics of a good publishing use case include:

• Start with where most publishers will start.  If you are in a high volume publishing environment, then perhaps you can assume everyone is already logged in and at the right place.  Usually, though, this isn't the case, and have to consider the log in process up to getting to the right place for publishing the content (sometimes placing the content can take time).
• Do not include any side-tracks, but do list the activities that will routinely occur.  If a publisher always has to include an image, then include that in the process.  If they rarely do, then exclude it.  If you plan on restricting what styling can be applied to the text, then include it.  If you plan on leaving this wide open, then this should be the same in the use case.  In other words, there isn't a one-size-fits-all use case, but needs to reflect your needs.
• Include the preview process.
• End with content being published to the live production environment, and viewed by an external site visitor. If multi-site publishing is a key part of your vision, then the content should appear on all the relevant sites.

Another key is to keep a razor focus on the maximum end-to-end elapsed time that elapses here.  In a news environment, perhaps the whole process needs to take less than a couple minutes.  In other situations, an hour may be acceptable.  In all cases, you obviously want to ensure that the publisher knows where they are in the process and what the next step is.

So where does this use case come into play?

• CMS selection.  CMS vendors usually want to emphasize the flexibility in their platform, but you need to keep your eyes away from the glitter at least long enough to make sure the simple publishing process is indeed simple.  Even if you have a simple use case, CMS vendors will want to emphasize all the bells and whistles during demonstrations.  Be bold and make sure that you see a walk through of your simple use case without all the possibilities thrown in.  In many cases, you will find that the straight through process is actually more crooked than it seems when looking at all the what-ifs.  
• Implementation.  Our attraction to complexity will perhaps spike during implementation, and so you need to make sure the implemented system successfully results in a simple publishing process.
• Training.  Training needs to be particularly high quality for this most common use case.

In sum, implementing your simplest publishing process may actually prove difficult, but at least you should be aware of this as early as possible...