I've got a unique perspective as I visit many businesses in a year and get to see their internal network structure. Judging from what I've seen most companies use a standard PC as a server for just QuickBooks or something else they share. If they do have a server it's usually just for sharing files. Very few companies use a server for applications. Cloud computing may seem like a big deal to major corporations but for small-to-medium businesses it's just going to be too expensive.
Apple would be better making the Mac mini server, marketing it to those smaller businesses, and making some money. And that appears to be what they're doing.
Actually the opposite. We install a lot of servers in small businesses, very small businesses, 2-15 employee's. Part for file share but more for running internal applications.
SharePoint 2010, Search Server 2010, SQL, etc...
Enterprise level search for a small business is very interesting to them and you need a local app server.
I'm not big on the whole cloud computing thing, I'd love to find the person who came up with the name and slap them.
Hosted Exchange is a PERFECT cloud app because it is incredibly high cost to run yourself in any business with less than 50 people with a real Exchange admin.
Beyond that....hosted SharePoint is useless for the most part although BPOS does offer more of the high level features turned on than the rest but still lacking. In a hosted environment most of the really useful features cannot be used.
Plus security is still lacking in most cloud initiatives. Google's use policy alone means most should not use it.
I do think Apple will need to come out with something like Windows Home Server and I wish they would. Low powered, low cost, expandable storage, just to host files since Apple is insistent on Aperture libraries and the like being hosted on a AFP share.