it is free verizon has just not discounted the phone yet, apparently they are waiting until the last minute when the I-5 is released but you can still do it through Apple if you want from what i have heard and just pick your carrier
Wescyde is completely right. I just did this. My wife wanted to update to the iPhone (and was fine with the iPhone 4), I ordered it though Apple (who will look up your Verizon account) and it cost me a total of $4.25 for shipping and tax. Ordered it on a Friday and got it on Tuesday.