I am a fellow veteran, Army Captain, Infantry Branch and wanted to throw out my two cents:
1) You have tremendous leadership experience that will be highly marketable to MBA programs and post-MBA.
That said, I think there are some things I wish I knew a year or so back to help me.
All of my suggestions hinge on your waiting and applying to full-time business school for fall '12 (Class of 2014) as you will not be too old and you will have time here to streamline some things to prep for Round 1 / 2 next fall.
If you have dwell time, just continue serving or seek short-term employment. I think a great option a lot of folks do is work as a Federal Consultant for 8-12 months at either Deloitte or Booz Allen. Both have JMO specific recruiting programs. Lots of people I know worked in a job such as this, polished up some professional certifications and then applied with post mil and civilian experience from well-known companies.
At this point this year, if you apply, and want to go anywhere with a good ROI you will be in Round 3 and not have time to re-take the GMAT or address your GPA
2) GPA is an area where you can tackle using extension courses, take 2-3 courses online and ace them. This shows your growth and ability to handle academics. Lots of people on here recommend Accounting, Stats, etc and they offer them for 600-800 through different state school extensions. A popular one is UCLA, UCI, or Berkeley.
3) GMAT, definitely take a course on this. Knewton (I have no affiliation) offers a 100 pt improvement. I also found GMATpill
helpful and very afforable. If you can even get up to the 650-670 range, you will be in business for top 25 programs and even higher
4) You will really want to plan this out strategically and tactically, essays take significant time. You will be drafting, running them by friends/spouse/etc and honing them.
It is best to knock out GMAT/a class or two from say FEB-mid JULY; on focus on these; once you get your target GMAT score then hit up the appropriate school websites and see where you'd love to go based on your interests and scores
Some schools I have found very welcoming to vets are listed below, they also offer fee waiver which if you apply to 4 schools will save $1K:
Highly Favorable to Vets - Great Vets Club + Fee Waiver: Darden, MIT, NYU, Columbia, Dartmouth, Olin, Cornell, Yale, Duke (not positive on the waiver here)
(Also these schools tend not to care if you are not a 24 or 25 year old where Harvard and Stanford might)
Highly Favorable to Vets, but you eat $250 App Fee: Harvard, Wharton
Essays will not come out until mid-late July / early August in most cases, that way you spend the summer visiting schools (budget 1-3 weeks) and then tackling essays so you can hit Round 1 deadlines well ahead of the early/late October deadlines.
5) Clearly, this is your decision, but this is just what I would have done. I got everything knocked out but missed critical round 1 deadlines for Penn and UVA because I had to re-take the GMAT. I stressed out studying and taking the GMAT and writing / drafting essays and also school visits so yea. The process has worked out for me so far, I got interviewed at both round 1 schools (MIT, NYU) and waiting to hear back. If I get in I will have much more credibility haha. I did not even think of or know about the extension courses and i had no time in command.
You deserve to take the time and really plan this out. You have sacrificed a great deal and it is better to be patient and strategic, do not undersell your leadership. It will take you a long way.
Please shoot me a message if you want to talk further, I wish you the best!
Also Alex sorry to hijacking your area, you are about 5000 times more knowledgeable than me