in the e46 line up, the sedans were released in September of '98 as '99 models. Coupes showed up a year later (in '99 as '00 model). The M3 showed up in roughly March of 2001 as a 2001 model.
Compare this to sedans... we have had '05 and '06 model years and are now on '07... going by this we should see the E92 M3 round about April - June 2007.
Comparing the E46 run to this one in terms of Coupes, we would be waiting until 2008 to see the M3.
Lets hope they are going by the sedan release!