is there a registry tweak i can do to make this or any other tray icon automatically hide always? For all Users

Looks like there is a reg tweak over at Kelly's Corner that partially accomplishes the task. Kelly posted a .vbs script, to wit:

Option Explicit
On Error Resume Next

Dim WSHShell, n, p, itemtype, MyBox
Set WSHShell = WScript.CreateObject("WScript.Shell")

p = "HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\EnableAutoTray"

itemtype = "REG_DWORD"

n = WSHShell.RegRead (p)
errnum = Err.Number

if errnum <> 1 then

	WSHShell.RegWrite p, 0, itemtype
End If

If n = 0 Then
   WshShell.RegWrite p, 1, itemtype
   MyBox = MsgBox("Show Inactive Icons in the Notification Area are now ENABLED", 64, "Show or Hide Icons in the Notification Area")
End If

If n = 1 Then 
   WshShell.Regwrite p, 0, itemtype
   MyBox = MsgBox("Show Inactive Icons in the Notification Area are now DISABLED", 64, "Show or Hide Icons in the Notification Area")
End If

Set WshShell = Nothing

So if one creates the DWORD HKCU\Software\Microsoft\Windows\CurrentVersion\Explorer\EnableAutoTray value and populate it with "0" or "1," then ALL tray icons are either hidden or displayed (reboot required). Don't know about setting individual icon values--I played with RegSnap without success--but nothing is impossible, I suspect. I hide them all and then manually show the few that I want after the install.

Take a look at the "ProgramsCache" below, after you change it that value changes. I've messed with it before but its been quite awhile and not sure if it act's properly. I hid one and that value HEX changed. The other is turning it on

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer]
"EnableAutoTray"=dword:00000001

[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\StartPage]
"ProgramsCache"

I realize this reply is almost two years late .... but just in case anyone does a search on the topic .... here is my method.

I get the icons setup to my liking, then export the following reg key "[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\TrayNotify]".

You can export it anytime, but it must be imported @ T-13 or in safe mode to work.