Also, another oddity I've noticed - start dragging the window from the bottom of the title bar, and drag it up against the menu bar. The window stops moving, but the cursor keeps moving as usual. Once you hit the top of the screen, drag downwards again. The Steam window moves immediately, even though the cursor isn't even over the window.
I tried to set my profile picture via drag-and-drop, but it didn't work. Turns out I need to click the small sphere (actually a label-less button I think) to bring up a picker dialog. Once the image is chosen, nothing happens (no indication that you've selected an image) until you click 'upload'. Also, since images can only be 150kb, it would be nice if the app detected that. I know it's WebKit and all, but what's the point in having a native app if it's not going to take advantage of it?
Still, this is a first release, and the automatic graphics switching is still quite new. I trust that the UI / UX issues will be resolved in due course.
Edit: Upon rebooting my Mac, the Steam client did not trigger an integrated to discrete switch. However, according to gfxCardStatus, the "steam" process was keeping the discrete card engaged prior to the reboot.
Also, some games play fine on the integrated graphics, so switching over to discrete isn't necessarily something you always want.
Though I'd guess the workings of this auto graphics switching mechanism are really Apple's responsibility.
After years of being derided as a games-less platform, Valve finally brings Steam to the Mac – but does it pretty half-assedly. I know a half-dozen developers who could have done a better interface than this.
I don't mean to sound ungrateful, and it's better to have it than not, but with the effort I'm sure it took to port the whole thing over to the Mac, I'm surprised that the little things (like copy/paste) don't work.
It's great that they're treating the Mac like a respectable platform, but this is going to be a terrible introduction to any Mac users who've never used Steam. My first impression was 'It's slow, it doesn't work properly, it won't download Portal at all, and the demos it downloads don't work.' Not exactly high praise.
It's got a fake Mac interface (doesn't respect the Graphite appearance preference) and normal copy and paste (⌘C ⌘V) don't work in some/all of the text fields.