I just did earlier today, and boy, all these stuff make me... feel... great.

My observations?
Observations?

• I noticed that a Nintendo Zone app was installed along with the update. Too bad I can't really use it because there are no Nintendo Zone hotspots around here.
• Nintendo 3DS camera now records videos. It records and stores video in widescreen, and I think you should be able to view it on anything that supports 3D video playback, and also anything as long as you remove the second video stream or something.
• StreetPass Mii Plaza should be renamed to Mii Plaza now. Why? It's now SpotPass (and hence Internet)-enabled, so you don't really have to go around in somewhere with a lot of 3DSes these days, aside from specific accomplishments (that tell you that you have done something) and certain pink puzzle pieces (requires actual people).
• An extra section in "Nintendo 3DS" section of data management - add-on content. DLC is coming. To something.
• System transfer is now enabled for 3DS-to-3DS.
• There's a built-in QR code reader now that can decode URLs and send you straight into it. I think it should also work with plain text. Just hit L/R in the HOME Menu, and tap the grid of stuff.
• Frame rate drops in my HOME Menu?

I've only had it a few minutes, so I've only taken some videos. The video works decently, nothing too special though. The camera quality on the 3DS really only works in daylight, you just get loads of noise otherwise... Well, it's still nice to have that feature. I just started up the Mii Plaza and I'm suddenly being flooded with achievements! :O

EDIT: I just spent a load of my Play Coins and I've now finished the DK Country puzzle (Except the pink pieces D: )
EDIT II: Amazing achievenent - Got three identical Puzzle Swap pieces in a row with Play Coins!

The first new puzzle for me was the Mario Kart 7 puzzle. I also spent a lot of play coins and completed 2 of the older puzzles I was still working on. I'm also enjoying the video recording features.

I've mostly been playing around with the videocamera mode on the 3DS Camera. I found out a bit of information about the video format, which allows you to convert your own videos to play on the system:

Motion JPEG, 20 fps, 400x240, PCM audio (most bandwidth and frequency combinations should be fine). Works best through Format Factory.

There are a few problems here, though. First, I believe it retains the 10-minute limit. I tried some episodes, but none of them would work on the 3DS. The files are also quite large for the abysmal quality (think of what basic cell phones record nowadays, or what online news videos were like around 2004) that you get out of it, at about 15 MB/minute, getting about 12 MB/minute without sound.

I think I might make a video showing off how to do it and some quality samples.

Yeah, I'm pretty familiar with the 4-bit ADPCM format, but Format Factory doesn't have that listed.

I got mine yesterday. Haven't noticed any changes yet. .-.

About the DLC thing. I believe that is likely for Sonic Generations and what-not.

I'll need to update it when I get it out of the box at the 25th... <.<

but it sounds pretty cool though.