Harvard posted on its admissions committee’s blog a few tips and guidelines for applicants considering applying to Round 3 (till 4.6):

“For those of you thinking about Round 3, here are some of the FAQs we field once application anxiety kicks in:

FAQ #1: Do I have to wait for my recommenders to finish before I can submit my application?
That’s an easy one to answer: no.
We hope that all recommendations will be received by noon on April 6. Of course, that rarely happens. Our advice: don’t wait until you get the notice that your recommendations have all been submitted before you hit the “submit” button for your application. “Late” recommendations received within a day or two after the deadline will be added to your file.  It’s your responsibility to make sure that both recommendations have been received – and for you to understand that we may render a decision based on whatever recommendations have or have not been submitted.  

FAQ #2: Can I submit my application without an official GMAT or GRE score? What about the TOEFL?
The key word here is “official” — you must have either a GMAT or a GRE score in order to submit your application, but your unofficial score (i.e., the score you receive the day you take the test) is perfectly acceptable. Please do have your official scores sent to HBS. We will verify scores of all admitted candidates later in the spring.
TOEFL scores are different. You can’t wait until the last minute to take the TOEFL because you won’t be getting a score on the test date.

FAQ #3: Is there any advantage to being “early” in a given deadline period?
No, not really. We don’t begin to read applications until after the application deadline. On the night of April 6, we will begin to distribute applications to the Admissions Board. Contrary to lots of speculation, there is absolutely no correlation between when an application is submitted and when, or if, a candidate is invited to interview. Applications are not reviewed in the order in which they are received.
That said, I wouldn’t advise waiting until 11:59 am to upload your application. We anticipate that server traffic will be high and you will be frustrated and anxious with the time it will take to have a successful submission.”

Harvard also recently responded to some common Round 2 myths:

Myth #1: There are no spots available.
Not true. We manage the selection process to ensure that there are always spots open for the candidates we want. Are there as many spots open as in Rounds 1 and 2? No. Are there as many applicants? No. Do I think a strong candidate has a fair shot? Yes.

Myth #2: We’ve run out of financial aid.
Not true. The very last person admitted to the class has access to the same need-based financial aid that the very first person received.

Myth #3: If I get dinged in Round 3, I can’t/shouldn’t apply the next season in Round 1.
Not true. There’s absolutely no stigma in re-applying 5 months later. Happens a lot. Many people in our classroom today were successful re-applicants.

Put Me in Business (applying in less than a year)
Put Me in Business (applying in more than a year)