I am not sure, but it seems like skyscape now offers some software for the new iphone.
http://www.skyscape.com/iphone/iphoneintro.aspx
Looks like RN notes and Davis drug guide are available. I am not sure if it is software that you load directly on the phone or if you just access it wirelessly. I hope it is direct software. With the recent price drop on the 8gig iphone, it is certainly looking to be my next acquisition.