Yes there are players that support simple visualisation, the one that springs instantly to mind is
Pocket Player which can even do fullscreen vis rendering, however they are limited to 2D vis only.
3D visualizers like Geiss and Milkdrop require a hefty amount of computing power and since 3D acceleration is only available in a very limited number of PDAs (your x50v is one of them BTW) the market for such a feature is limited.