For me that would suffice - but its not the answer, I'm afraid. Management/IT wants to:
- have workflows, so documents can be approved among other stuff
- have document lifecycle, so they expire and must be reviewed after time x
- solve the Dropbox problem - how do you collaborate with external entities without compromising security by having users uncontrollably put stuff on Dropbox, because there is no other way?
- have automatic versioning
- be able to checkout/lock a file during editing
These are just a few aspects. You can do most if this by gluing stuff together yourself, but these are the constraints:
- be able to achieve all this with semi-competent IT staff
- seamless integration into the existing Windows infrastructure is a big plus
- be able to blame someone else if something goes wrong
The problem with the semi-competent IT staff is that they are not immune to Microsoft's BS^H^H PR. They will really believe what the account manager told the CIO over dinner.
Email + shared folder (as flat as possible) with rigorously enforced naming conventions. Clever features like search can be added with crawlers.