I pray to baby jesus that when I get mine for christmas that Lumines is either still original or the original version is easy to find. Same with Metal Gear Ac!d.
edit: I suppose I could buy them now, but I'm lazy.
According to Bebpo on the negative side Popolocrois for PSP:
--Ghosting is insane and bad. When you move it can hurt your eyes if you try to focus, but the second you stop it looks gorgeous. Your eyes adjust but wow it's odd.
--Loading is worse than the PS1 game (loads when enemies appear, loads when moving into new screens)...but loading enemies in on the main map is still shorter than your average PS2 rpg battle loading so it's very managable.