Apple is not "dropping support" by making SL Intel only. They are just not developing the newest OS for old hardware. On the release date of SL, your PPC Macs running Tiger and Leopard (and Panther if you still use it) will not spontaneously combust. Just as Apple still released security updates for Tiger now, they will continue to release updates for Leopard for probably two years after SL comes out so now it will be three years down the road before they "don't support PPC platforms"