Just think about the basic difference between a netbook and a mobile phone and consider what if Android turns into a great netbook Operating System with its particular command to netbook and other such sort of devices. But keep one thing in mind that there is also room for an affordable, but super portable device that allows you to do a lot of things online.
If this device can be netbooks, it could be a good option, but the problem is that they can only be used in suitable locations where network connection or Wi-Fi coverage is available.
It seems that Google has been considering that sector too for sometime, as it might took only few hours to run Android on the some Asus netbook. It seems that two product polices have been designed for Andriod that leads the OS in two particular uses. The first one is for handsets and the other one is for the Internet devices like netbooks.
However, the OS is just a part of it and when it comes to netbook portability, they must be usable anywhere and just like Dell Inspiron or the Advent 4213, they definitely require built-in 3G.
Contract is another issue which has been observed with 3G, and it makes netbooks affordability factor quite less attractive. But it can be because of the fact that netbooks these days are being sold just like PCs whereas they need to be sold like handsets.