Well... There is the empirical way to find out if it is true or not.
Since a logic 1 for the LPC2148 (ViH) is about 2 volts, and you assume
that a 10K pullup goes to a +3.3volt rail. Remove your 10K pullup from
one of the JTAG pins, then, assuming a voltage divider would be needed
to GND on that pin, put a 20K resistor from the pin to GND. Then
measure the voltage. You should see about 2.2volts there.
That should give you about 110ua of drain on that pin.