I've had a 3D TV for about a year and a half (and I got a second one about a month ago); the PS3 has a lot of fun 3D games right now that look and play quite nicely. If you liked Killzone, then you'd probably get some mileage from Resistance 3 as well. Uncharted 3, Tron: Evolution, the Motorstorm games and the recent God of War compilations also look nice in 3D. Looking forward, the Ratchet & Clank compilation will support 3D as well.
3D definitely adds a new dimension (pardon the pun) to the experience and anybody who has a 3D capable set should definitely check it out.