Intel still tries to follow its tick tock launch logic. Tick is a minor shrink and change of the existing core while Tock is the real deal.
Nehalem is the tock planned to start in late 2008 and at some point in 2010, probably very late, Intel will replace the Nehalem marchitecture with something it today calls Sandy Bridge.
Intel has a CPU planned for 2009 codenamed Westmere, but we suspect that is a Nehalem at 32nm that will make for reasonable thermals on eight-core CPUs. If we had to bet, the 32nm Nehalem derived and renamed to Westmere will launch in late 2009 as a server and high-end desktop part.