Thanks to high-resolution formats such as DVD-A and SACD, we can work with greater dynamic range with surround mastering and can escape from the pointless battle for more loudness.
Delivering audio in formats such as AC3 and DTS are also part of the mastering engineers range of tasks. Conversion should be carried out with caution; the behavior of data reduction processes should be taken into careful consideration.
In my service portfolio, I limit myself to the optimization of surround sound and the delivery of common surround sound formats for authoring.
Since various format questions (DVD-A, Blueray, HD-DVD, etc.) have yet to be definitively clarified and since I do not have image processing and desktop publishing capabilites, I refer to specialized studios when necessary.