I got my iPad a few hours ago and was bound and determined to be able to edit Moodle content on it with the HTML editor. After upgrading to 1.9.11 I thought this might just work automatically, since it now works with Chrome & Safari but it didn't.
Now I can.
1. Download the Terra browser. It's free. It looks better than Safari (more like Chrome).
2. Click on Settings, it looks like a cog just like on the homescreen on the top right.
3. Click Identify As
4. Select FireFox 3.6
5. Now so can you.
I'm sure there's more to come, but this is the most important as far as I'm concerned. This thing just paid for itself.
Edit: The only thing I can do at this point is to select text and affect the changes that way. To bring up the keyboard you have to click settings, and identify again as Safari Mobile and use your keyboard there. You can get the keyboard to pop up if you want to type in HTML mode.
Unfortunately at this point it involves a little toggling back and forth.