I guess I'll give my own review of the game.
I picked up [Protoype] yesterday after work and I've got about 2.5 hours under my belt. I think the game is really fun, you get to feel like a complete bad *** running around New York and running up buildings at the same time. Once you get a handle on the controls combos and special moves become second-nature.
Don't expect this to look like GTA IV graphics wise. I will admit I was disappointed in the graphics. The sound is awesome, though. If you're hooked up to receiver you can play the game in DTS which is sweet. My sub-woofer got a nice workout while I was ridding the city of infected vermin.
The ability to take the form of anyone in the city is pretty cool. It adds a certain splinter cell feel to the game when you need to lay low.
The voice acting is really great and the story pretty good as well. Overall, this is a rental at best. But, if you have $60 burning in your pocket, I'd say go ahead and pick it up. It's a complete action game and believe me, when your running full steam across the rooftops of lower Manhattan you'll get a smile on your face.