CO Insider posted the news on Flyertalk.

United’s 100,000 mile flyers earn six systemwide upgrades, upgrades which can confirm an international upgrade at booking (or whenever the seats become avilable) from most fares. (United 1K flyers also get 8 confirmed domestic upgrades per year.)

American’s top tier flyers get 8 international upgrades per year valid on any fare.

Continental is a bit stingier — 4 confirmed upgrades per year valid intenrationally (as well as domestically) and good on any fare without co-pay. So while fewer instruments than United, there’s no fare requirement (perhaps a sign that United might do away with the minimum fare rules on their systemwides?).

Each systemwide upgrade on Continental will be valid one-way on Continental metal (including Continental Micronesia and Copa). They’re transferrable, and are confirmed out of R inventory (F inventory on Copa). Finally, once credited to your account the systemwides will expire at the end of the following Elite year. So upgrades earned in 2010 will expire in February 2012.