And its possible after the events in the Avengers SHIELD had to come out of the shadows. People on this show certainly have heard of SHIELD by now at least. But yeah, I agree with Nam. I think what they do exactly (just like most government agencies) is relatively unknown to the public. You get what their purpose is, but not exactly what they do to go about doing it.
The one thing that still bugs me about Iron Man 3 is the total lack of SHIELD. I know they got a lot of backlash from so much SHIELD/Avengers build in up Iron Man 2, but SHIELD was a constant presence in both IM 1 and 2 and the complete lack of it in IM3 was jarring. Especially when a terrorist is making threats directly at the president. I would have thought SHIELD would maybe have an interest in that. So I hope they explain a bit of that in Captain America 2 because I think Cap's lack of presence or mention as well was odd - especially with them really pushing Iron Patriot. Its like they were trying to appeal to that Captain America patriotic angle, but yet try not to mention him at the same time.
I guess its just the inconsistency of SHIELD's portrayal in all of these different movies and TV shows is the problem. They are secret, but the they aren't. They meddle with everything and then nothing. I just wish they'd dump the kindergarten agents and deal more with the higher ups. I'm hoping Maria Hill is at least a regular next year now that How I Met Your Mother will be over. That could help a bit. As much as I'd like Fury to be a regular, I don't see SLJ wanting to be tied down so much to the show. A few appearances a season would be great though.
and it's going to suck having to wait. 
