Seems like a lot of people are into this - including a co-worker. I always assumed it was a overhyped supplement. But looking at Wiki and then PubMed abstracts, I'm not so sure. It seems to have a fair bit of linoleic acid... It certainly doesn't seem very paleo.
I'd like to know whether the science claims are solid or ambiguous.
Reservatrol is supposed to be the most beneficial component, but supposedly that's been proven to be false. I don't know that I trust much of anything that I don't test for myself however.
You simply need to search Pub Med: http://www.ncbi.nlm.nih.gov/pubmed?term=Trans-Resveratrol and http://www.ncbi.nlm.nih.gov/pubmed?term=grape%20seed
Personally, I take Trans-Resveratrol, Grape Seed, and Pomegranate extract in a single pill, made by Vitacost. I take that to battle a benign tumor I have (along a ketogenic diet, and other natural supplements). I will be having my next checkup in a month to see if I'm winning that battle or not. One thing I did notice though by taking this supplement is that I'm not sore after exercise as easily anymore.