Yeah… That. That’s the biggest drawback (I just switched from an iPhone to the HTC One, and the Rdio app was driving me nuts). Google will be missing out on a huge portion of its potential customer base if it doesn’t release an iOS app. After all, it did beat Apple to the punch. Might as well rub it in Apple’s face (if Apple approves an app, of course).
This will put Rdio to shame—the Google Music website, IMO, is already better in terms of responsiveness. Add to that the “HTML5” lab (meaning no Flash), and Google’s 320 kbps MP3s, which I’m sure they’ll offer streaming, since they already have them. Awesome.