Samsung Today 2 is already on your Omnia, it just has to be enabled as an option. This can only be done by modifying the registry. You need a registry editor to do that. PHM offers one for free.
Be careful modifying the registry. Make sure you backup any Key before you modify it. That way you have a chance at reversing your change should you make a mistake. Once you have PHM or another registry editor you have to browse to
or create this key:
[HKEY_LOCAL_MACHINE\Software\Microsoft\Today\Items\ Samsung Today 2]
Then you have to add the following items underneath that key:
"Order"=dword:00000003
"Flags"=dword:00000000
"Enabled"=dword:00000001
"Options"=dword:00000001
"Type"=dword:00000005
"Selectability"=dword:00000002
"DLL"="secst.dll"
Registry values are sometimes case sensitive. Make sure you have it EXACT.
One you're done, close the editor and do a soft reset (power off and back on). Then you shoudl see Samsung Today 2 in the list of options for Today screens.
Or, you can install the cab above.