Cory
The AT89LS53 datasheet specifies a power supply current of 25mA at 12 MHz as well. A graph at the end of the datasheet plots "typical" power supply current vs clock frequency from 0 to 24 MHz at 25 dg. C and 6V, 5V and 3V. The 5V plot appears to be linear, from 7mA at 4MHz to 11mA at 12MHz and 15mA at 20MHz. The AT89LV51 specifies 20mA at 12 MHz, and its "typical" graph reveals currents of 7, 10.5 and 14 mA (these are my "guess"timates). Perhaps you can infer AT87F52 values from that.

Chris