I haven't been on these forums lately, due to me being on LBPCentral lately, but LBPCentral is down, so I guess I'm going back here. I just got the game on December 25th for the PS3 and a few glitches happened. Nothing major, but still worth taking a screenshot of.

http://i2.lbp.me/img/ft/e221a697928e770de62cc611ffc045a9179479bd.jpg
Everything is gone. Every planet.

http://i7.lbp.me/img/ft/0376b41d72f1c7e231b3b8b39c46fd33003c3498.jpg
This is a LBP2 level and this person used the layer glitch. LBP3 thinks that these layers are apart of the regular game. So I am able to walk all the way back on them, meaning that this LBP2 level allows me to walk in all 16 layers. Which is something that you aren't usually meant to do.

http://i0.lbp.me/img/ft/5007ab8979d6316a398619a6aec9362201cde59f.jpg
I was playing a level involving a glitch that had the model of a Earth, but it was transparent. Afterwards, Bumkun turned transparent. This also stopped me from editing Adventure maps, it would just reset to the default layout. It was fixed after restarting.

Those are some nice observations. What I think they should do with LBP1 and LBP2 levels is restrict them to the normal 3 layers that they were meant for.