Native editing for Google Docs will be available on the iOS device closest to you within the next few days -- if not already.
Google issued a press release this morning, complete with a demo set to some snazzy music demonstrating the new editor in action. Google said that the it will be available on all iOS devices, plus those with Android version 2.2 and higher, within the next few days. You need iOS 3.0 or above to run the mobile Google Docs editor.
I grabbed my iPad and saw that I could already edit my documents. For basic editing of your projects on the fly, it's not bad at all. But, it's very basic editing at best and does not have any support for styling text or customizing spreadsheets like Documents 2 Go and Quickoffice do.
For video of Google Docs on an iPad (among other devices), click the link below.