TUAW posted a news story that Apple won't support iPhone to iPad tethering
If you thought that when iPhone OS 4.0 gets released and you can buy the 2GB "Datapro" plan for $25, along with an additional $20 per month to tether your iPhone's WiFi connection to your iPad, think again. It's just not going to happen. This is consistent with Steve Jobs' answer to an email asking him about this possibility. His response was a terse "no."Apple won't support iPhone to iPad tethering
According to Apple, once enabled, you will be able to tether your iPhone to a PC or Mac either via WiFi, Bluetooth, or a USB cable, but they didn't make mention of the iPad. It turns out that WiFi isn't possible on the tablet: the required Bluetooth profile isn't enabled, and using the camera connection kit to connect to a mini-USB port on your camera won't work either, although it will work with a USB keyboard and headset.
