Beer Advocate has a hops guide, here's what it says about Centennial:
Centennial is an aroma-type cultivar, bred in 1974 and released in 1990. The genetic composition is 3/4 Brewers Gold, 3/32 Fuggle, 1/16 East Kent Golding, 1/32 Bavarian and 1/16 unknown.
A relatively new hop on the market, this hop used to be called CFJ90. Described by some as a "Super Cascade" and we tend to agree, but it's not nearly as "citrusy". Some even use it for aroma as well as bittering. Bitterness is quite clean and can have floral notes depending on the boil time. (alpha acid: 9.5-11.5% / beta acid: 4.0-5.0%)
At Radio it's served in a chalice for $6. It's a dark brown, with a quickly dissipating head. However the remaining foam clings well to the glass (both a function of the beer and of a clean glass). It's opaque. It also appears to have some things in it that add to the opacity, it doesn't look like yeast, or anything that would be wrong, it just looks like it's unfiltered.
It smells woody and sweet. I didn't get a citrus or pine aroma. I got wood. It wasn't completely an industrial arts class in highschool smell, but there was wood.
It felt thick, almost a wee bit syrupy. Additionally, it seemed too cold. (A function of the cooler). I allowed the beer to warm up a bit, and that produced even more of a woody smell.
It tasted oaky, sweet, and then bitter. It wasn't piney or citrusy. The hops provided... bitter. If you were going to make a homebrew and wanted something to provide bitterness, this would be a good one for it. As you see from the hops guide, it does have a large amount of alpha acids, that contribute to the bitterness.
It was a damn fine beer. It was both mouth watering from the initial sweetness, then drying from the bitterness.
The woody-ness of it reminded me of New Holland's Oaked Mad Hatter (without the sweet tarts).
I'm going to need to try it again (probably at Crane Alley) to see if it's always this woody. I expected more pine, although citrus should be more evident (after reading more about the hops).