They manufacturer them with good quality hardwood stocks (walnut) stocks, too. Didn't you see them at the gun store before you bought yours.
On the left nav of this linked page check out the Tikka T3 Hunter, T3 Laminated and T3 Deluxe.
http://www.berettausa.com/product/product_rifles_main.htm

Don't worry about the stock you have though. These like most synthetic/composite stocks on many manufacturers' rifles and shotguns are extremely durable.They'll take a tremendous amount ofhard use. They are a little lighter. But if you end up having to do many miles of walking up and down elevation when you hunt with this or any other synthetic stocked rifle or shotgun you'll come to appreciate that lighter weight.
You can always trade it for another Tikka T3 with a walnut or laminatedstock as they come from the manufacturer. Or as I do, keep it and buy another down the road!