According to tech documents found on the AMD's website, the 2400+ will run at 2.0GHz (133.3MHz x 15). Your math is correct also, so should you get the CPU running at 166.6MHz at the 15x multiplier, then it will run at 2.5GHz. Also, it is alleged that the 2800+ has a 13.5 multiplier at 166.6MHz FSB to run at 2.25GHz. Therefore I would expect the 2400+ to run at multiplier of at least 13.5 when you have the FSB at 166.6MHz to give you 2.25GHz. Several review sites said that the 2400+ will reach 2.4GHz easily. That implys that it is difficult, though not impossible, to get to 2.5GHz. Until we hear from some end-users though, we really won't know how this chip performs.
Anyway, the answer to your question is yes. Peace.