According to the X-bit crew, Intel's getting ready to ship 64-bit processors for the masses. The Pentium 4 500-series will include EM64T, & will be priced similarly to the current 500-series generation of chips.

"Intel’s lineup of EM64T- and EDB-enabled Intel Pentium 4 processors 500-series will consist of models 571, 561, 551, 541, 531 and 521, which are clocked at 3.80GHz, 3.60GHz, 3.40GHz, 3.20GHz, 3.00GHz and 2.80GHz respectively."