It is absolutely possibe to postion one storage system for both VM datastores and user file data.FC/ISCSI/CIFS/NFS (Depending on which Hypervisor) can be utilized for Hypervisor VM datastores along with CIFS or NFS foe user network shares. For a small environment like the one descibed, a FAS2520 would most likely be adequate.* With this platform, you would need 10GBaseT connectivity. The FAS2552/4 platform would be the sweetspot for small medium size businesses for mixing Block and File workloads to serve as Hypervisor and file sharing for user community. With the addition of Flash, the FAS2500 series makes a great platform for VDI platform as well.
I have several school and public sector customers about the size described using the FAS2200 and 2500 series with great success.
*As always, performance report gathering and NetApp sizers should be used to determine platform and flash/spindle count.
As sstafford said, yes, that's completely doable with a NetApp. We just installed two FAS8020s because we wanted the backup/recovery options of NetApp, but also so we could do away with out servers running home directories and shares. Our user data will be migrated to a CIFS share while the VMs will use NFS on the same NAS.