This is a design decision made by the Windows Phone team at Microsoft and the home screen has been this way since Windows Phone 7 up to Windows Phone 8 GDR 3 (or Update 3).
Has anyone else noticed this?
You bet. There are very active discussions about this taking place on:
- WPCentral: Screen blank space at the top
- Windows Phone User Voice: Start Screen Improvement - Remove excess blank/black space from the top of the Start Screen
In the case of the latter, you can add your vote(s) to the issue.
Is there a fix or workaround?
No workaround at this time. Windows Phone 8 is constantly being updated though so having an option to adjust that empty space is always a (in my opinion, unlikely) possibility.
Edit: More research on whether this can be done by building an app
I wanted to find out if there were any API's out there that might allow me to build an app to eliminate the blank space. Since Windows 8 and Windows Phone 8 share a lot of their source code, I wanted to find out if there were any Windows 8 API's out there that would allow me to change the positioning of tiles.
Turns out I am not the only one who has been thinking along these lines...
What it boils down to is that there are no API's that might allow developers to do such a thing (yet) and any other way of hacking this will probably not be approved for the Marketplace anyway!