Just a quick one to give something back - we wanted to automatically name our stations to the service tag when provisioning. Here's a simple PowerShell script which you can save as rename.ps1 or something and then just add as a PowerShell distribution package and set as a provisioning step. Tested and works on all our Dell machines with Windows 7 and latest PowerShell, other manufacturers may vary but worth a go.
$computername = Get-Content env:computername
$servicetag = Get-WmiObject win32_bios | Select-Object -ExpandProperty SerialNumber
If ($computername -ne $servicetag)
Write-Host "Renaming computer to $servicetag..."
Rename-Computer -NewName $servicetag
Write-Host "Computer name is already set to service tag, nowt to do!"
Hope this helps!