CNN article regarding workarounds for Wi-Fi issues. Maybe helpful for some of those experiencing problems.
http://www.cnn.com/2010/TECH/ptech/04/07/apple.ipad.wifi/index.html?hpt=T2
http://www.cnn.com/2010/TECH/ptech/04/07/apple.ipad.wifi/index.html?hpt=T2