Yes, those speed options were available before. Up until now the iMac models had faster CPU options (the slower iMac option matched the faster MacBook Pro option). Now the MacBook Pro offers two models with the same speeds as the iMacs, but without the upgrade option to 2.16GHz.
Minor correction, your power equation is incorrect:
Voltage: V = I * R
Power: P = I * V
-- or --
P = I * I * R = I^2 * R
Yes, those speed options were available before. Up until now the iMac models had faster CPU options (the slower iMac option matched the faster MacBook Pro option). Now the MacBook Pro offers two models with the same speeds as the iMacs, but without the upgrade option to 2.16GHz.
I assume the iMac will be getting a similar speed bump? Kinda silly have laptops available with faster procs than the desktops.