Reg hack works for me as well, from 2 machine Vista business/Win Xp. Both were around the region of 1.5k++ pings. Pop the hack in wala.. i get around 300++ to 500++ depend on how many users were logged on local LAN. So far i haven't really tested whether it affects other issues e.g. download, BT and such. But so far i have no issues.
Anyway, i made 2 .reg files for me to turn on "WOW" mode or off it

So when i ever i'm ready for it i just double click it and reboot. Sure a slight hassle but hey.. beats having 1k pings. To off it.. just double click it again and reboot. I don't download AND wow anyway
Here's the snippets: Wow mod ONCODE
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\{9DB7BEB4-6944-4C2A-8493-401A49B7582B}]
"TcpAckFrequency"=dword:00000001
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSMQ\Parameters]
"TCPNoDelay"=dword:00000001
Copy the above and paste to a file with *.reg extension.
NOTE Remember the interface is
YOUR interface serial number. Save it e.g WoW-on.reg Double click and reboot.
Wow mod OffCODE
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\{9DB7BEB4-6944-4C2A-8493-401A49B7582B}]
"TcpAckFrequency"=-
[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\MSMQ\Parameters]
"TCPNoDelay"=-
Double click it again and reboot. Back to normal
P.S. This has been tested on Win Xp and Vista. Also make sure you patch vista like the post before this had stated. Vista 64 uses QWORD instead. Again... the interface seriall is
YOUR interface and change appropriately.
Please do this at your own risk, which i doubt would be of any harm but heck.. just backup your registry