So far, I've done a good job of talking about the idea of the beer, now I'm going to talk about the actual beer. Deschutes' The Abyss is categorized as an Imperial Stout. I'm going to slide it into the Russian Imperial Stout category as recognized by the Beer Judge Certification Program (BJCP).
Out of the bottle and into the glass...
Just like an IPA to India, a Russian Imperial Stout was overhopped and had a higher gravity to withstand the journey from England to Russia and surrounding regions. However, as many dimensions as an IPA may have, the Russian Imperal Stout can have many, many more. For example, an IPA brewed with black cherries ends up being more of a novelty than a by-the-guidelines IPA. Not that this type of experimentation can't produce a wonderful IPA, but strictly speaking, the beer is starting to leave the IPA category. With a Russian Imperial Stout, you can almost thow anything into the black void--fruits, spices, herbs, etc.--and still remain within the category. The complex, roasty malt bill and high alcohol content are usually enough to calm down a lot of other ingredients and push them to the subtler areas of the brew.
The BJCP Style Guidelines say that the overall impression of a Russian Imperial Stout should be: "An intensely flavored, big, dark ale. Roasty, fruity, and bittersweet, with a noticeable alcohol presence. Dark fruit flavors meld with roasty, burnt, or almost tar-like sensations. Like a black barleywine with every dimension of flavor coming into play." 
The elusive bottle of Deschutes' The Abyss.
Deschutes Brewery says "This exceptionally popular imperial stout, aged in French oak, pinot noir, and bourbon barrels since March 2007, has immense depth with its rich and complex flavors. True to its name, subtle notes of coffee, chocolate, molasses and licorice pull you in deeper and deeper. Cherry bark and vanilla bean added during the dry-hopping process are the proverbial “cherry on top”!"
You'll definitely notice all of these flavors and more, especially if you pair it with different foods. This is not a session beer, so relax and enjoy it with your favorite meal or snack.