I've researched most of these programs heavily, but I have not done a special masters program (yet!). So keep that in mind. But these are my thoughts:
These programs do NOT boost your undergrad GPA. Rather, they give you a new graduate GPA that you can use to show your academic capabilities if your undergrad performance was poor to borderline. This graduate GPA could make up for your undergrad GPA, but it does not improve your undergrad GPA.
Georgetown, BU and Drexel are some of the most popular and most effective of the special masters programs. However, Drexel does not award a master's unless you stay for an additional year to get your MMS degree.
I would be hesitant about NYMC. They are only now keeping a track record of the success rate. Also, it is spread out over two years. This loses the design of special masters programs (i.e., challenging and heavy courseload in one year).
I would also be hesitant about Loyola. A student in the program, coredump, has mentioned some inside details of the program that you might want to check up on. My initial problems looking at the program are that it is only in its first year, it is only 24 credits, there is no research component, there is no lab component, and you don't take classes with the medical students at Stritch. And that's just what I can think of now.
Roswell's Interdisciplinary program, if I remember correctly, is also two years. Again, that loses the point of the special masters program (i.e., challenging one-year courseload that simulates the medical curriculum). The oncology emphasis could have its advantages, but the program is simply not as established as the other special masters programs and again, the coursework is not like other special masters programs.
Barry sounds like a good curriculum to me, but it simply is not as effective as the others if you're going for an MD school. However, it seems to be a good osteopathic feeder. In fact, I think some of the profs in the MS in Biomedical Sciences program teach at Nova Southeastern's osteopathic school. The classes you take are sometimes shared with the podiatry students, but you don't take actual medical courses. Also, the program is pretty expensive. If you're gonna drop a good deal of cash, spend it on a more effective program. I also understand that the one-year program is supposed to be very intense. And yet, it isn't nearly as effective as the better known programs. Hard work without the results you want would suck.
EVMS and UMDNJ I think are also good programs. I considered both. EVMS is one of the true special masters programs because it's one year, 34 credits (I think) in one year, most of your courses are with the med students, and you do a thesis (library-based). I could be wrong about this, but it also seems to have a solid informal linkage to EVMS. One think that sucks is the price tag though (but it's comparable to G-town and BU).
UMDNJ-Newark's MS in Biomedical Sciences also has its advantages. You can take classes with the medical students, but it's probably not quite as hardcore as a program like Georgetown's which has more credits and more medical school courses. UMDNJ also has the thesis component, which could be either an advantage or disadvantage. But keep in mind that the typical time for the UMDNJ program is 1.5 years. So it's not the best program if you're applying this year. Another advantage is the price, which I recall is much cheaper than EVMS, Georgetown, and Boston U. I've been in contact with an NJ resident that did the program and it seems that the program is very effective for students trying to get into either of the two UMDNJ MD schools. The area isn't the best in the world though. That's my only real problem with the program. Apparently UMDNJ is in the process of building a graduate housing complex, but it doesn't open until Fall 2006.
Of the ones you've been accepted to, forget about Barry and Roswell if you're looking to be competitive for MD schools. Barry is good for DO schools. Roswell, I know little about, but it's definitely not as established as the others. EVMS and UMDNJ are solid options.
Of the ones you're waiting on, forget Loyola and NYMC. Loyola is poorly designed and as far as their guaranteed interview goes, you need to *average* 28 or better on the MCAT (e.g., 26 + 28 = no interview). Georgetown, Boston U, and Drexel are all good programs. Georgetown and BU are much more expensive, but in my opinion the programs are worth the cash...and you'll get a degree out of it. But Drexel is much cheaper if you're there for one-year and is arguably the best pre-professional graduate certificate program (Loma Linda and VCU are the other certificate programs that sound pretty good from what I've gathered). Drexel's IMS seems to be a love it or hate it program though. Check out the old threads.