Well there is good news and bad news. Total cost of ownership(TCO) will be greatly reduced and the lifecycle of your workstations will be greatly increased. Heck you can run a Citrix client just fine on a 6 year old Windows 95 computer.
Another bonus to this design is that you only need to update the software on the server and then all users automatically have the update. The amount of time that you will need to spend on each workstation in your firm will be minimal.
The down side? If you have problems with your server(s) everyone has problems. Systemic problems are no fun.
How many users do you have? A decent server can onle realistically handle 20-25 connections. If you have more user's than that you will need multiple servers. You will also need multiple servers for fault tolerance if you want failover capabilites in case one server fails. Multiple servers start to raise TCO again.