I have the 3G ipad but only use wifi, haven't activated a data plan. I notice that my ipad handles wifi unlike any of my other devices. They, imac, MB Pro ipod touch, iphone, drop their wifi when in sleep but the ipad never drops it. I check this by going into Airport utility on my mac, I use an Airport Extreme base station that all my devices connect to by wifi. Airport Utility has an Advanced section that shows all wireless devices connected to the network and their signal strength, noise and transmission rate. My ipad is always showing as connected, asleep or not. The other devices will drop out of the displayed graph when they go into sleep but not the ipad. So however wifi is implemented on the ipad it's very different from all the other devices. This may be one reason why I've never had the issue of the ipad losing its wifi when coming out of sleep. Actually the only wifi problem I've ever had is that every now and then the wifi antenna symbol will completely disappear triggering an alert that says connecting for a few seconds when the antenna reappears and the connection is made again. Weird but it happens very infrequently.