How long will it be before we see an iPad teardown?
You could try downloading SMART Utility (Google it) and see if it reports any problems in the attributes of the hard drive. You could also run the short and long tests The software isn't free but it does have a demo period where you can try it out.
Looking at the picture in step 8 and seeing where the RAM is located in the later pictures, would it be possible to change out the RAM without lifting out the logic board? It looks like there's a gap big enough to reach in an unlatch them. And is there any special voodoo with the hard drive (do you need to use the same manufacturer or could you replace it later with any other)?
I noticed that the picture doesn't show any Kapton tape on either end of the Airport cable. Is that the way the iMac came or was the tape removed before the picture was taken?