The vast majority of those applying for Resolution 42 gets approved (percentage-wise is in the 90s). The exact number can be found in a JAOA article but it's thanksgiving and I'm too lazy to look it up.
Before this year (July 1, 2008), you needed an exceptional circumstances as part of the requirement for Resolution 42. That exceptional circumstances was granted 99% of the time. Hence starting this year (July 1, 2008), the exceptional circumstances requirement was eliminated.
So now to get your ACGME PGY1 year AOA approved via Resolution 42, you need to do the following
1. remain a member in good standing with the AOA
2. Either attend an AOA conference (or regional osteopathic conference, or osteopathic specialty college conference) or giving a presentation during your residency on something osteopathic.
3. Meet the rotation requirements.
http://www.osteopathic.org/pdf/sir_ogme1core.pdf
Check out the link - you can either meet the traditional rotating internship requirement OR the specialty-specific internship requirement.
If you meet all 3 - all you have to do is apply and your ACGME PGY1 year will be AOA-approved and you are eligible to get an unrestricted license in all 5 states that require an AOA-approved year.
People who run into trouble getting their Resolution 42 approved is usually due to curriculum requirements