In my case?
Yes. Oh, yes... Absolutely. I have been a gamer since the tender age of twelve. I have played (or, in some cases, endured) long hours of good old Dungeons and Dragons, of World of Darkness, of computer myths such as Baldur's Gate or Neverwinter Nights...
Now, up to what point gaming has shaped my writing? I wonder about that. There's some gaming habits I consciously apply to my writing (mainly, the story arc structure planning) and there's some gaming traits I consciously suppress (like the hero characters). All in all, I like to think that gaming has been another experience in life that has helped me to improve my story telling abilities, but I guess the reader must be the one to judge.
How about you?