Hi Ken,
Hopefully the Win 7 typography team will make this "feature" optional by SP1. I'm holding out until then. But if you insist on using 7 before the font smoothing is fixed, here's how to deal with registry font substitutes and UAC/system protection.
Edit the registry settings under FontSubstitutes so that "Tahoma" appears before Segoe in any FontSubstitute settings. Then, take ownership of the Windows directory (I took ownership of all subdirectories and files, which might be excessive, but made other tweaking easier to deal with) to delete Segoe. To take ownership, right click on the Windows system folder, select "Properties", click on Security, Advanced, then clik on Owner in Advanced security settings... Click on the edit button and change owner to your own account . Make certain "Replace owner on subcontainer..." is checked.
It's overkill, but will get it done.
R5N
P.S. If anyone does figure out how to remove font smoothing from the Win 7 taskbar, I will praise you for all of time.