Fr. Bourgeois might be facing more than excommunication
Update, 14 Nov 2008: Vatican spokesman Rev. Federico Lombardi makes the perplexing statement that Bourgeois' "excommunication would likely be automatic, requiring no further action from the Holy See". I don't know what this means. "Automatic" excommunication occurs upon the commission of a canonical crime (1983 CIC 1314), not upon the expiration of a deadline. What CDF appears to be doing is fixing the date for the formal imposition (1983 CIC 1331.2) of an excommunication; there's nothing "automatic" about that. I haven't seen CDF's letter, so I can't say for sure, but then, Fr. Lombardi says he hasn't seen it either, so I wonder, should he guess at what it says?
Of course, none of this confusion would arise if Western canon law would simply do away with "automatic" penalties completely, as Eastern canon law did (CCEO 1402). Poenae latae sententiae delendae sunt.