4745454b :
Movies will be fine, but games will have issues. The GTS450 is at best a midrange card already and 3D by its very nature will cut your frame rates in half. (left and right) So if in best case you were getting 50FPS, you now get 25. Not saying don't do it, but be prepared for bad frame rates on newer games.
yes there is also this points, for gaming the frame drops are very high, because there is need to run 2 games at same times from different point of views and also there is all the deph calculation that will drop frames by more than half, but at 720 and lowering some graphics [some times you have to remove some effects for the 3D Effect work properly] you can get acceptable framerates, but the fps drops are HUGE in gaming (unless you are using side by side/checkerboard/etc... so the processing will be done by the television, so the graphics card frames will only drop a little and you will be able to run at 1080i )
here is a list of games that you will be able to run without nvidia 3d vision, so you can plug your computer to your 3D tv ready activate the 3D option and the television will do the work (your television must be using the same conversion that the game will be splitting the image)
List of games with native 3D:
1 Avatar: The Game 1 1 x Platinum-A (100%)
2 Battlefield 3 1 1 x Platinum-A (100%)
3 Crysis 2 2 1 x Gold-C (85%)
4 Deus Ex: Human Revolution 2 2 x Gold-C (90%)
5 Sonic Generations 2 2 x Platinum-D (100%)
6 Trackmania 2 : Canyon 1 1 x Gold-C (95%)
7 Trackmania Nations 1 1 x Gold-C (95%)
8 Trine 1 1 x Platinum-A (100%)