I have a 3GS that is not eligible for upgrade through AT&T. However, I can trade-up via Radioshack's iPhone 4 promo for $25+tax. I already know this: 1 - I will lose Applecare since it will not transfer to the iPhone 4 (since it's an upgrade). I don't know this: 1 - Will I have to get another 2 year commitment with AT&T? 2 - Will I have to pay AT&T extra for upgrading my iPhone since I am ineligible to upgrade? (doesn't seem fair since I'm not buying through them?) I would assume yes but expect the worst because AT&T would know.