Paul, the ''trans-Mexico Canal'' rumor has been around for quite a few years and once again was debunked by Latitude 38 in their June (I think) issue. Their view was that one only has to consider the cost involved, the small user base, the ambitious priorities of President Fox, and the alternatives that current exist (a marina at the N end of the Sea of Cortez is well equipped to haul & transport cruising boats wherever they are needed) to recognize it sounds way too good to be true.
There''s a similar rumor about an ICW being finished down the east coast of Mexico, to attract powerboats and sail south from Texas, LA, etc. Some small segments have been done adjacent to marina developments but there is no funding, public or private, to tackle such a huge project at this time, based on what I''ve seen in print.
For more info, consider regularly reading Latitude 38''s Changes in Latitude column. Available on-line (www.latitude38.com) or in the free monthly magazine, which is distributed by all West Marine stores.