The ICMJE (International Committee of Medical Journal Editors) has announced a new format for Disclosure of Competing Interests. The policy, outlined on the ICMJE website, (which has been updated recently by the way and is worth a look at) also includes a form that has been adopted by the ICMJE member journals, and which the ICMJE is encouraging other journals to consider adopting.
Sheldon Krimsky & Erin Sweet from Tufts University, Massachusetts, USA have studied the conflict of interest (CoI) policies of over 200 medical and toxicology journals. They found that about 85% of the journals had a written CoI policy but in many cases these lacked specificity or were of limited scope (eg covering only certain types of financial interest).
See Accountability in Research 2009;16:235-53
The article is not Open Access but the abstract is available on Medline.
Findings of a study on retractions funded by COPE were presented by Liz Wager at the recent Peer Review Congress in Vancouver as a poster and picked up by Nature Medicine. You can read the report in Nature Medicine October 2009;15:1101