http://www.osteopathic.org/inside-aoa/Pages/single-gme-accreditation-system-faq.aspx
Here's an faq link that answers some of these questions. Apparently DO programs must register with the ACGME by 2020 and can start as early as July 2015. We will likely have to deal with the change which will affect MD and DO students. Here's the kicker though, if an MD student wants to apply to a DO program they will have to take OMM classes or receive OMM training as many DO residencies require that as a pre-req (and this will apparently not be changing). So if MD schools don't wish to offer osteopathic training to their students, it makes me wonder how those students would meet the pre-reqs to apply to the DO residencies...
I do not know if MD students will be required to take COMLEX to get into DO residencies, but they will have to apply to both the MD and DO match just like DOs who want to enter an allopathic program. Additionally, there will continue to be 2 separate matches for the time being since these agreements are being made between the AOA and ACGME while the NRMP is not currently involved:
Will there be a single Match?
The Match is administered by the National Residency Match Program (NRMP) and not the ACGME. Consequently, this is an issue that can be resolved only when NRMP joins our discussions. However, if all programs are considered ACGME accredited, it is likely there ultimately will be one Match.
So while it is likely that there will eventually be one match, it is also very likely that this won't happen until after the class of 2018 finishes our match.