The long awaited demo for LBP will be hitting the Playstation store today.  Here are the specs:

Brand new intro level with new stickers

Three story levels for that kingdom

New introduction video

Access to two community levels

Also includes a few creator tools for experimenting

File size: 1017 mb

I'll be downloading this tonight when the store updates just for fun to see how it all looks.

I also want to add that if you have bought the GOTY edition and are finding that the ModNation code is not working it is because the beta has not gone live yet so your code won't work until the beta is fully up and running.