well, depends. if your workstations are on 10Mbps then yes, pretty much any 100Mbps switch will help. We binned our 10/100Mbps switches last year and now have 100/1000Mbps or just plain 1000Mbps switches.

Of course, depending what sort of state the wiring is in you may have to rip that out to see the benefit of new switches. I don't think older cat cables will carry gigabit speeds properly.