Ok, my initial judgement of this app is kind of conflicted. When I read the description, I really wanted to like it, and I still want to like it, but there's just not a lot to it.
In summary, it's feels like a stripped down web browser dedicated to "surfing"only Pandora and Last.fm. You get practically the identical interface if you visit these sites in Firefox or Safari. A few extra bells and whistles are thrown in to add "convenience" but somewhere deep down I feel like they're just there to disguise the fact that's it really just a mini web browser.
There are 3 advantages of using Musicality over your standard browser...
1. You can close the window and the music continues to play (ok, this is nice).
2. Global keyboard shortcuts (and Apple Remote integration) to control the music outside the application window.
3. Growl song notifications.
That's pretty much it. Now here's where the conflict comes in. Are these 3 conveniences worth $15? Unfortunately I'm gritting my teeth and saying no. They have a launch special of $10, but I'm still hesitant at that price. I just don't see the value in paying double digits for this app. BUT, I do have the solution! :-) I hate suggesting copying the functionality of other program, but if they were to add the ability to record streams and stream wirelessly to my Airport Express (like *coughing* PandoraJam) I would pay $10 for this in a heartbeat! Maybe even $15! :-)
There are also some issues to fix. Why is it that when I click on any action that doesn't involve playing music, it takes me OUT of musicality and into my default browser (which is Chrome at the moment). It shouldn't have to leave the app, particularly since it's a web browser itself, to update my profile, find a song or get HELP. If those buttons aren't integrated with app, then they're kind of pointless.
Also, there's no indication that your Pandora music is being scrobbled to Last.fm. That should be a no-brainer.
I'll continue to play with it some more to see if it grows on me, but I can't imagine this becoming a part of my software collection in it's current incarnation.