There are already a lot of new android phones that is for me better than Iphone. Thunderbolt is one. But i wouldn't consider these phones as iphone killers,
1. People buy because of brand (who uses the phone and the like)
2. Let's face it, Apple developers and/or software developers has a lot to offer when it comes to iphone applications.
There will never be an iphone killer not unless Apple will seize to make new and better models.
Regards,