They changed the contents of manual1. Look at those speeds. All X2 parts default to 8Mhz and the all new shiny 20X2 (didn't even know that one was coming) can run at 64Mhz!
[Edit] Rats! that one is a "future product" oh well....
Supposedly Rev_Ed will be shipping the PICAXE 20X2 on April 6.
Check out the new manual2: You can run a program stored on an external EEPROM that means 32 external mem slots. You lose I2C functionality when you do that though.
You can even update your own program by reading it from an EEPROM over I2C...from code!