I bought the Resident Evil Degeneration game on the iPhone for $6.99 and tried it out. The graphics and sound effects are humble and the story does not really immerse you that much. The game design is very linear. The control scheme which uses a touch screen Directional Pad works and is actually quite impressive that they pulled it off without affecting the gameplay. You must play the game with the iPhone horizontally to give enough space for the D-Pad and the control buttons.
Overall, iPhone is great for games like Word Fu and Booty Blocks, but a game like Resident Evil IMO is best left on the big powerful consoles. Even a PSP version can be a lot more immersive. Capcom used the same control scheme from RE4 and RE5 but for an iPhone game. Well overall, its decent but as a fan of the series, this does not live up to my expectations. For someone who has never played the series before, this can be a good choice if they feel like putting up $7 for it.