Corporate Video has to be in 4:3 ??

Ok so I was shooting another coporate yesterday

and my lighting guy was telling me they are almost always given to clients in 4:3 finished format. IS this generally true?

Because until now, I have been giving them 16:9 DVD's and no complaints.

However, I was wondering if its possible to have both?

Can DVD studio pro format a DVD so it will play on 16:9 TVs, or play in a letterbox on a 4:3 TV??

If I DO need to resize my 16:9 HDV image to 4:3, what is the best way to do this?

I tried changing the sequence settings, but if I change the frame size of the sequence, it doesnt give me a 4:3 canvas, it just shrinks the resolution I think of my 16:9 images, but it remains in widescreen format.

please help?

Thanks very much for any help, much appreciated!