UAL772IAD, in the US, you should add Northwest as A330 operator... and to stay in North America, there's Air Canada as well (not the A332, but the A333 in their case), not to mention Air Transat and Skyservice.
Otherwise, you've got Lufthansa, Scandinavian, Air France, Swiss, Austrian, Aer Lingus, Air Caledonie, Air Greenland, Air Luxor, Air Madrid, Birdy, BMI
, Cathay Pacific, China Airlines, Corsair, Cyprus Airways, Dragonair, Edelweiss, Egyptair, Emirates, Etihad, Eurofly, Eva Air, Garuda, Gulf Air, Iberworld, Korean Air, LTU, Malaysia Airlines, MEA
, Monarch, MyTravel, Nova Airlines, Philippine Airlines, QANTAS, Qatar Airways, SriLankan, Star Airlines, TAM, Thai, Thomas Cook UK and Volare.
SAA also currently still operates one, but that, like LH
's B767, is just a stopgap measure.
And Air Algérie, Asiana and KLM have ordered A330s but aren't operating them yet.
Factoring in the fact that the B767 has been flying since the early 1980s, while the A330 started appearing on airports in the mid 1990s, I'd say that the list that they've accumulated isn't all that bad...