Here's my idealized system. I think it would be a considerable improvement for both traditional and nontraditional students but it requires tearing things down to the brass tacks.
First, medical school is now three years. I'll get to the structure of this later, but the basic thing is the first basic science year is mostly either dropped or integrated into what is typically the second year classes during the "new system" first year (anatomy and physiology would be discussed here in both the context of normal and abnormal, for example. Normal histology would be taught along with pathology)
So, classes like biochem, genetics, embryology, etc. would now be considered prerequisites for medical school. So, let's start how this affects traditional students. So, this requires a fundamental change at the undergraduate level. Now, with increasing requirements for entry many undergraduate campuses start offering an official "Premedicine" major. The prototypical premedicine major would be pretty open during the first and second years of undergraduate, with the typical student would start taking the basic science classes (Bio/Chem/Physics) as well as other classes to meet university/college graduation requirements like English/Composition, History, Sociology, Art, etc. Because students are free to pick their own classes, it's common for them to focus in an area they like and use that for a minor second major. Double Majors in History/Premed or Finance/Premed as well as Premed with a minor in Spanish, for example, are pretty common and add to individuality. Also, the premed "Major" would work similar to an honors college with set academic standards...if the students are not meeting certain GPA standards they asked to find a new major.
The third and fourth years of the premed major are basically the basic science first year of medical school divided into two years. So students take embryo, basic micro, maybe an introduction to/basics of sanatomy/physiology (although these are still integrated into the new first year, see above) biochemistry, etc. etc. However, students are also given "real life" medicine exposure during the third and fourth year of the premed major. For example, a class like "Introduction to Medical Systems" would have students spend days with doctors, nurses, pharmacists, physical therapists, etc. Hopefully, this exposure to clinical medicine as well as the upper level classes in undergraduate would allow students to make a more informed decision about their career.
So, that's pretty much it for the traditional premeds. But what about nontrads? Well, they would be required to take increasing prerequisites, but they would get the benefit of decreasing medical school to three years. The prerequisites could be taken either as a dedicated special masters program, but for those who don't want to give up their career while they're working on the prereqs they can take one or two classes at a time. The introduction to medical systems type class would be optional, especially for those who are working in allied health professions. In addition, the system would weigh the grades in these new prerequisite classes to help nontraditional students who may not have had as an impressive undergraduate GPA.
The MCAT would stay mostly the same...maybe move some things around but it will still test biological and physical science as well as an interprative section. Drop the writing section though.
So, this is getting long, so how does the three year medical school work?
New First Year: Basically, this is the old second year. However dissection would still be integrated into an organ systems approach. Physiology would be taught along the lines of Pathophysiology. We move all classes on ethics and such into didactic sections that are taught in their respective clerkships. For example, informed consent may be taught in surgery, end of life care in internal medicine, etc.
At the end of this year, students are given a summer break they use to prepare for the "Basic Science" Licensure exam, which basically takes the place of Step 1.
New Second and Third Year (First half): We move away from the old system which basically forces students into following a generalist path in third year. All students are required to start with a "Core" rotation however: Medicine, Family Medicine, Pediatrics, Surgery etc. to get them used to working in a hospital, writing notes, etc. After that, students are free to rotate through whatever they want. You want to see ENT? Go for it. You want to try some radiology? They'd love to show you. Interested in Emergency? Nothing's stopping you.
However, there are a few caveats. You have to rotate through all core clerkships before you graduate. There is also a "Clinical Medicine" licensure exam you must take before you graduate, basically taking the place of Step 2, so many try to take all of their core stuff before they have to take it.
Second half of third year: Interview season is now moved to January, February and March. This allows students more time to rotate through all areas they want before committing to a field. Note, however, the interview season is much more compressed, and uniform across specialties. In addition, the time between end of interviews, rank list date, and match day is also compressed. So the new match day is the first Thursday in April.
Now obviously many students are going to use their vacation time during the interview months, and students also have the option to continue rotating through different fields or meeting their core clerkship requirements. However, now schools start offering some more "practical medicine" classes. They teach how insurance medicaire work, how to be a succesful businessman, how to invest/save, malpractice etc.
Why do I think this system is better
1) Less first year doldrums as well as less redundency for typical premeds.
2) Undergraduate students are given a formalized exposure to medicine and hospital systems during premed
3) Decreased cost by dropping a year
4) Dropping the assumption that all students are going to be general medicine or FP doctors by how we have them rotate. I think this will actually make more students INTERESTED in being primary care, because currently we are forcing them to rotate through it first and then basically "Hiding" subspecialties for as long as we can, and then they start seeing subspecialty fields in an idealized way. If we give them freedom to make their own decisions, I think you'll find more students come to FP or IM of their own free will.
5) Going along with 4, students get better exposure to all areas of medicine and make a more informed choice about what field they want to pursue.
6) The classes at the end of third year better prepare students for the realities of healthcare and how to be succesful.
Wow, that ended up long.
