Tab Close Control 2.0.0 has been released. Get it here.
Besides a whole code checkup (using Javascipt enclosures (tech info here)),
a few options have been added:

Only one option no longer seems to work in the latest beta of Firefox 3.1: closebuttons everywhere... does not show a closebutton at the end anymore.
Anyway, I don't think many of you use this option.
Enjoy.
PS: did you know you can open a new tab by doubleclicking on the empty space next to the last tab...