There is a very well advertised e-book on the web that advocates de-leafing to an extreme degree.
Each season I remind myself to try this method (on just one plant) but for some reason I can't bring myself to strip a tomato plant of almost all its leaves - just leaving a few at the top!
It is certainly a good idea to remove the lower leaf branches up to the first truss.
This will improve air flow and help prevent bugs and diseases from getting out of control - it also helps a plant send its nutrients to the parts that are most in need, that is the fruit and growing tip.
It is standard practice for professional growers to remove leaves up to the truss that is fruiting. This means that as tomatoes ripen, all leaves are removed below the truss with the ripe tomatoes.
Eventually most of the plant is without leaves but this is all done gradually over a period of weeks and months and I believe this should not be attempted over a period of just a few days - unless you want to send your poor plant into shock!