Store is BEING updated - Xenogears has appeared. No Show demo just yet.
If you really wanna get it right when it comes up, use the text search in the upper-right corner of the PSN store - sometimes things get posted on there (like Xeno) before they actually appear in other areas of the store
Thats how it was for the NCAA 11 demo as well, 6 is the magic number for demo's it looks like, ncaa came out at that time as well.