Intel is moving very quickly into an all dual-core lineup, getting ready to offer dual core Xeons, Pentium 4s, and Celerons. They aren't abandoning single-core processors just yet, though, and the Yonah core will see another release within a year for budget laptops and perhaps budget desktops. Of course budget meaning cheap in this aspect. Like the development of the Celeron, it seems that all Yonah core may be dual-core, but single-core varieties will simply have the second core disabled. This is very common in the PC industry. The top clock speed for the Yonah isn't known yet.