No, you can still watch in 2D high definition on your 3D TV's screen.
Disney, Dreamworks, and many other major producers are working to assure that their products will still be available for viewing via 3D TV. Blu-Ray has developed a new 3D player that will play regular 2D DVDs as well as new 3D DVDs on 3D TV.
JVC Professional Products has created an IF-2D3D1 Stereoscopic Image Processor that serves as a 2D to 3D converter by combining left and right eye images. Toshiba and Samsung are also working on 2D-3D conversion systems.
According to a Quixel Research survey 46% of consumers are very interested in having a 3D TV in their home. Screen Digest predicts 1.2 million 3D TVs in American homes by 2011.
There are some people who cannot see in 3D. For example people with amblyopia (lazy eye) or astigmatism have trouble detecting the depth in 3D movies. Also if one eye is more near sighted or far sighted than the other, he or she may have trouble seeing 3D.