<p>What do you think the benefits of functional programming are? And how do they apply to programmers today?</p>

<p>What are the greatest differences between functional programming and OOP? </p>

It doesn't have to be one or the other: using a language like C#3.0 allows you to mix the best elements of each. OO can be used for the large scale structure at class level and above, Functional style for the small scale structure at method level.
Using the Functional style allows code to be written that declares its intent clearly, without being mixed up with control flow statements, etc. Because of the principles like side-effect free programming, it is much easier to reason about code, and check its correctness.