I thought the point of Xbox Live Arcade was for, you know, quick arcade games.
If it's up to the developers themselves where their games appear, despite the original platform, maybe some select PlayStation games might show up on the Virtual Console? It's not like having a 2D CastleVania game makes anyone want to buy PS2/PS3/PSP CastleVania games - if anything, it might encourage people to buy the GBA/DS CastleVanias which are similar.