I saw those last night. I was wondering, but wasn't able to find out -- the videos, are they compressed time? Or 1:1 time? Because the one of the flare is absolutely amazing.
I don't know the duration, but would be surprised if that huge structure lasted more than a few hours (due to the lack of visible rotation of the feature -- the rotational period of the sun is about 27 days as seen from Earth).
The spatial scale is also awe-inspiring. The diameter of the prominence is about 1/6 that of the Sun. The Sun is about 110x the diameter of the Earth. This means 15-20 Earths would fit, end to end, inside the magnetic loop. For another point of comparison, see:
This is cool, but I'm a bit underwhelmed that NASA labels its OWN immages as "stunning".
Seriously "NASA's New Eye on the Sun Delivers Stunning First Images" is the kind of press flack hucksterism we'd decry if any other firm promoted itself that transparently.
Keep in mind that the instrument developers who built the two imagers onboard have spent the last ~10 years of their life working largely on this project. For many of them, it will be the crowning achievement of their career. The results are likely to reshape the discipline due to the increase in spatial and (especially!) temporal resolution.
To get this thing to work, they had to overcome a lot of technical obstacles, including thermal stability of the focal plane and optics (it's a high-resolution telescope that mostly sits in the sun, but goes into Earth's shadow regularly, altering lengths of optical paths), and bandwidth issues (a set of 16-bit 4096x4096 images every ~10 seconds).
Finally, and this is not made clear in the press materials, they're exploiting some neat spectral effects to get unusual "images": spatially-resolved velocity (thru Doppler shifting of spectral lines) and spatially-resolved magnetic field (thru the Zeeman effect). That is, an image of local magnetic field. Those calibrated images are a main driver of the science -- although the flare pictures are cool.
Putting it all together is an impressive technical feat.
http://science.nasa.gov/science-news/science-at-nasa/2010/21...
[1] Speaking as one of the site developers, not to take credit from the scientists