Over the weekend the new name Core i7 for the Nehalem Bloomfield Intel CPUs was leaked. Today Intel officially announced Core i7.
Intel's new Nehalem microarchitecture will be formally branded Intel Core processor. The first products in this new family of processors, including an Extreme Edition version, will carry an i7 identifier and will be formally branded as Intel Core i7 processor. This is the first of several new identifiers to come as different products launch over the next year.

The Intel Core i7 processor brand logo will be available for high-performance desktop PCs with a separate black logo for Intel's highest-end Extreme Edition. Intel will include processor model numbers to differentiate each chip.
Initial products based on this microarchitecture are expected to be in production in the fourth quarter of this year. These processors will feature Intel Hyper-Threading Technology, also known as simultaneous multi-threading, and are capable of handling eight software "threads" on four processor cores.
Intel does not explain why the company use 7 in the Core i7 name in the press-release. It potentially means the 7th overall CPU architecture Intel released over the years.