I will tell you that a lot of the comments and thoughts on this thread are right on the money.
That being said, I will give you some observations and issues you might want to consider in making a final selection. Remember, this is coming from my time in a civilian agency, however, the intel discipline is pretty damn consistent no matter where in the USG you fall.
1. You better like to think critically, brief and write. That will be the majority of what you do during your time in intelligence (the Powerpoint comment was dead on). It won't be "sexy" either; you will feel, at times, that you could strip the uniforms/emblems and you'd be left with your typical office envirnoment that could substitute for an insurance company in Peoria, IL (not that there is anything wrong with Peoria, I think...).
2. Do not consider intel if you are not comfortable defending your position and/or calling someone out on a conclusion if you disagree. Remember, your analysis and assessement will be used to make decisions with significant implications. Your analysis/conclusions may lead to bombs being dropped or missiles fired, and most importantly, sailors/US service members putting their lives on the line.
3. Intel is a support function; it allows the warfighters to do their job and decision makers to make that decision. This is not a blanket rule but it is holds a lot of weight. You may be preparing questions for interrogations or debriefing a pilot after the flight but you won't pulling a trigger (unless you are overrun god forbid).
I have three years and change in intel and it has been good while it lasted. Ultimately, it is not for me. I have always wanted to fly and the planets have aligned to make that happen. If that doesn't work out, it will be either Surface Warfare or EOD as they are very hands on and very much "Navy" jobs.
I add that aforementioned comment because a key thing to ask yourself is if you like being a tactical, hands-on, "get a task and knock it out" sort of person or if you are more of a strategic, long-term project oriented person. Not to say that you will never criss-cross the two; it is just the way I have viewed my time in. I have discovered that I really am of the former and want that sort of designator in my Navy career.
Again this is from my experience and may not necessarily jive with those with Navy intel/ONI experience. They are just points to consider when putting down your selectors.
Hope this helps and good luck. Oh and brush up on your Excel and Powerpoint too. Remember, yellow highlights in Excel give the decision-makers bright, smiley faces.