The idea, it seems, is to point out how much more widely available Opera is, and how free it is (disingenuous, I’d suggest, since all handsets cost money, not just iPhone; and all handsets come with built-in software, just like iPhone).
(And that goes for “free” handsets, too, which you still pay for via your fixed-term contract fees.)
The new features look pretty good, and I particularly like this note from the developers:
Opera Mini 4 beta installs beside your current Opera Mini version without overwriting any of your existing files or settings.
How nice to see a dev team that’s thoughtful enough to tell users a little thing like that before they go ahead and start downloading…