I think Groo has it as "late 2007". I'm not sure the 65nm node is typical for Intel, because they are saddled with the EOL'd Netburst architecture. So, if you don't count that one, then you would only have 2 (or maybe 2.5 counting Yonah) generations, the Merom(/Conroe/Woodcrest) and Nehalem. And Whitefield might rapidly move to 45nm after launch.