Good news for Wubi users - Natty Narwhal 11.04 is out and it is probably the safest Wubi install for some time, mainly due to all the grub2 fixes that came out recently.
There's one gotcha that was missed during development and this is that Wubi, when run standalone, will still give you the choice between Ubuntu and Ubuntu-netbook. However if you choose Ubuntu-netbook you'll get an error message that it couldn't download the metalink.
What's the reason? The netbook-edition in Maverick was basically the same as 32-bit Ubuntu except it included the Unity interface. With 11.04 the newly rebuilt Unity interface is now standard on regular Ubuntu, so there's no need for a separate Netbook-edition.