Here's my little roadmap for Apple products (in this case, the eMac would likely stay just behind the iMac in terms of speed):
Mid-August:
- PowerMacs reach 1.33GHz
- 166MHz System Bus
- 333MHz DDR Memory
September:
- 1GHz PowerBook
October:
- iMacs reach 1GHz
- Bump to 133MHz system bus
- DDR implementation similar to Xserve
- iBooks reach 800MHz, still G3s
- Classic iMac discontinued
January:
- G5 announced (from IBM)
- Runs at speeds up to 1.5GHz
- 64-bit processing
- PowerBook bumped to 1.2GHz (still G4)
- DDR in the PowerBooks
February:
- iBook moved to G4 processor, no MHz jump
March:
- iMacs bumped to 1.2GHz
April:
- iBooks reach 1GHz
Mid-August:
- PowerMacs reach 1.33GHz
- 166MHz System Bus
- 333MHz DDR Memory
September:
- 1GHz PowerBook
October:
- iMacs reach 1GHz
- Bump to 133MHz system bus
- DDR implementation similar to Xserve
- iBooks reach 800MHz, still G3s
- Classic iMac discontinued
January:
- G5 announced (from IBM)
- Runs at speeds up to 1.5GHz
- 64-bit processing
- PowerBook bumped to 1.2GHz (still G4)
- DDR in the PowerBooks
February:
- iBook moved to G4 processor, no MHz jump
March:
- iMacs bumped to 1.2GHz
April:
- iBooks reach 1GHz