Lightroom 4 was recently released, the first major release in over two years. Adobe regularly updates Lightroom but with each major release comes change! Lets take a look specifically at the Develop Module.
The biggest and most significant change comes in the "Basic Panel". Not only are there new sliders, but some of the olde sliders now work differently.
I could go in depth and compare and contrast to version 3 but I think this would only makes things confusing. Lets try to forget what the old sliders did before and concentrate on what they all do now.
I've listed the main sliders of interest and what light spectrum they address within a photograph. Over all each slider is more (but not absolutely) modularized in so far as what part of the light spectrum they address. I think this new approach makes MUCH more sense and will be easier to understand and use. If you "mouse over" the different sliders the specturum that they address will be highlighted within the historgram. This is a good way to remember what earch slider will do.
The sliders are listed below and identify what part of the light spectrum they work on within the photograph. You should use them roughly in a top down manner.
Exposure - Works on Mid-tones only, it will no longer clip highlights when you increase exposure.
Contrast - Works as you'd expect.
Highlights - Similar to the old Recovery but only works on Highlights and will not effect mid-tones.
Shadows - Similar to the old Fill but only works on Shadows and will not effect mid-tones.
Whites - Used to control Highlight clipping.
Blacks - Used to control Dark clipping.
Much of the rest of the Develop Module works as before.
The above video does a great job of recapping the changes, thanks to Olaf Bathke a German photographer who did a great job on this video. This guy is not only an incredible photographer but he really knows Lightroom. Amazing what he can do with this tool.
Another nice review article with demonstrations.