Tabs are mostly implemented now and will be available in the next update!

Here's a screenshot:

That's how I plan to implement this: as an additional feature so that you can still work with Textastic as you are used to.

Actually, that's already possible. Have a look at the "Text" menu: Shift Left / Shift Right commands.

Selecting text and pressing Tab and Shift-Tab works, too.

Many applications still use the old menu items. But if you take a look at Apple's apps like Preview or TextEdit, you'll see that they have the same File menu as Textastic.

Yes, version 1.0 is too aggressive when registering supported file types. I've already changed this and it will be fixed in the next update.

For now, you can use "Get Info" in Finder and choosing a different app as the default app for all files of that type should work, too.

Textastic uses the new standard file handling in Lion and Mountain Lion.

If you click on the "File" menu and press the alt key, the "Duplicate" command becomes "Save As".