The Google Chrome OS setup on a netbook will be friendliest to users who plan to use their secondary computer in locations with a wifi connection (iPad does offer a 3G model starting at $629 + monthly data plan). Since the OS is based on an Internet connection, it won't work well for users who spend most of their time on a train, for example. But it does work well for literal laptop use—the iPad offers a special keyboard dock with a full-sized keyboard, but that only works on a flat surface. Users who need to type a lot will probably prefer a netbook to an iPad More : Netbooks Run More Applications Than the iPad ?
Google Chrome OS will not be for everyone. Mac users who never liked the Google Suite in the first place are unlikely to jump ship when Chrome OS comes out. Those who need to be able to access the web anywhere will want to shell out some extra cash for a 3G iPad and a data plan. But for many Mac users, Chrome OS on a netbook will be the way to go.