Windows 7 and the school network

Not been able to post much lately due to huge workload involved in rebuilding the entire school network during term time. Why? Don't ask, it's a long story. When this is all finished (I think) we'll be the only school in the UK running Server 2009 and Windows 7 across a whole site. Whether this is a good idea remains to be seen. No, it will work. Keep repeating "it will work!" over and over.