Hide or not to hide the system tray in a Windows Phone 7 application?

I am debating whether to hide or not to hide the system tray in a Windows Phone 7 application. I've not found any general suggestions on this issue -the official Windows Phone design guidelines don't address this issue at all - except for Jeff Wilcox's blog post who suggested that he personally likes to see the system tray in applications. I'd like some general advice on this issue from other Windows Phone developers.

Some reasons for showing the system tray are

Doesn't take up that much space
Users may want to see it at times

Reasons for hiding it are

You can't control its background: unless you're using PhoneBackgroundBrush as the background the top row will stand out
Lots of widely used / official apps already hide it: all games as well as the official Facebook and Twitter app.

I'd appreciate all advice on this.

Solution

Transparency and colors are now possible with Mango by setting its BackgroundColor and Opacity :

shell:SystemTray.IsVisible="True"
shell:SystemTray.BackgroundColor="Transparent"
shell:SystemTray.Opacity="0"

I would say by default show it unless it really gets in the way in a way you can't workaround, especially if its an app and not a game.