I think you should definitely apply now. I applied with the expectation that I would get waitlisted or denied, and then focus on the areas of my application that were weak and reapply next year. However, I lucked out and got admitted. Here were my credentials/stats:
*1 year CTICU experience (with IABPs, VADs, ECMO, and heart/lung transplants)
*undergrad GPA 3.3, nursing GPA 3.8
*GRE score 1280 and 5.5 (540 in verbal, 740 in math, 5.5 in writing)
*I had also taken graduate courses while I was an undergrad that I did well in (all As), so I made sure to point out that I had already experienced success in graduate courses (and therefore would be a successful graduate student).
I made sure to emphasize that although my experience appears limited, I made the most out of it by attending as many educational opportunities as possible (IABP class, VAD class, ECMO class, Advanced 12-lead EKG class, etc) within the hospital's educational offerings. Although I did not have ACLS, PALS, or CCRN by the time I applied (my hospital makes you wait six months after orientation is over to take the ACLS class...weird, I know), I made sure to address that in my personal statement and in my interview. I said that I was registered to take the next ACLS class, and that I had already begun preparation for the CCRN exam.
As far as the interview went, they only asked me one clinical situation. I was aware going into the interview that there may be concern about my maturity level (considering that I am only 24 and competing for a place against RNs who were a bit older with much more experience). I made sure that I was calm, rational, and confident in my decisions regarding patient care.
Apply as soon as you can...if you get denied, then make sure to ask what you can do to make yourself a more attractive candidate and then work on that area and reapply next year!