1) Netbooks are cheaper. and after you spend all that money on accessories and upgrade options for the iPad, you'd be able to buy three netbooks for the same amount of money.
2) With a netbook, you can multitask, allowing you to run several apps at the same time.
4) Netbooks have USB ports, about two to three on average. The iPad has none.
5) Higher Resolutions. There are several 10-inch netbooks that offer 1,366-by-768 resolutions, namely the HP Mini 5102. The iPad tops out at 1,024 by 768.
6) Netbooks have options for bigger screens. You can get one with an 11-inch or 12-inch widescreen.
7) Removable batteries. You can buy an additional battery for your netbook if you want, allowing it to last for multiple days.
8) They have physical keyboards, so you don't have to spend extra money to buy a physical one that docks.
9) Multiformat card readers are built into every netbook, so you can download photos and videos from your camera.
10) Netbooks have an Ethernet port and some have a Gigabit Ethernet. Thus, if the Wi-Fi's throughput is not enough for streaming HD video, you can always plug in a network cable.
11) Netbooks can run a full-blown Windows OS.
12) You can choose different 3G wireless carriers with a netbook.
13) You can print files from a netbook.
14) Netbooks have more networking capabilities, such as the ability to map to drives and printers.
15) You don't need another computer to sync your data.
Courtesy of PC Magazine 02.01.10