Nope, gigabit speeds are meant mostly for LANs, so upgrading from 5 to 6 with a gigabit switch would increase your file transfer rates between your PC, htpc, or nas, but I haven't heard of any company offering gigabit speeds to homes. Someone correct me if they have, I may move there.
oh ok i see so there would be a bottleneck from the ISP to my house anyways, so the better cabling at my house wouldn't play a factor?
Think of it like pouring a bottle of coke down a well. The big opening in the well has no effect at all on how fast the coke pours out if there is more room or more cable speed than is needed. The extra is totally wasted. Much like getting faster cable (big opening in well) is going to have no advantage when the internet is less than 10-Gigabit (coke pouring) and passes through.
Also note that cat6 is rated for up to 10-Gigabit transfer speeds. The standard NIC using in todays for motherboards are only 100mbps to 1000mbps. The extra 9 Gigabits of speed would go absolute wasted and is used more in business networks etc, not home networks. Unless you got some hefty networking hardware in the thousands of dollars.
Cat5 is more than enough at 100mbps to 1000mbps for any home internet plan.