Using the zoom feature on your Blu-ray remote does that for you. The choice is literally at your fingertips already. If CBS-D were to create 16x9 versions, it wouldn't look any better than zooming it yourself. Heads would be chopped off, the saucer of the Enterprise would be chopped off, etc.
No, that's not right at all.
When a studio does the cropping, it's usually done in a "smart" way, with at least some attempt made at shot composition. Depending on what's important in a given scene, the general wisdom is to position the matte just above the heighest head.
If you use the zoom function on your TV, you will simply get the centre of the 4:3 image throughout - making many, many shots look bloody awful.
For the record, I hate cropping of 4:3 material.