The iBooks have only recently been updated (only 78 days ago according to the Macrumors Buyer's Guide), so based on the typical rate at which Apple updates products, it seems unlikely the iBook will be refreshed at MWSF. However, there have been price cuts in the past day or two on the iBooks in several countries (don't know if that includes the U.S.).
In any case, you only have a few more days to wait and find out. I don't think purchasing anything at all this close to MWSF is a good idea.