I'd like to contribute a rather slick workaround for regular Excel users in Windows 7.
Create a folder anywhere on the hard disk - it doesn't matter as long as you can find it.
Name it a blank character by holding the right Alt key and typing 255 on the num pad.
Now create a shortcut to "C:\Program Files (x86)\Microsoft Office\Office12\EXCEL.EXE" (may differ), name that blank too.
Now right click the task bar → Toolbars → New Toolbar... and add the blank folder. This will add a little Excel icon which you can click on to open a new instance of Excel from the taskbar.
You may have to unlock the taskbar to move it around.