* Task Navigator area on the left is 80 pixels wide
* Statusbar/titlebar area is 720x60 pixels
* Application area of 672x396 pixels is in the middle
http://maemo.org/development/documen....html#overview

I think the resolutions are the same on all devices. Also if you use the hildon and gtk programming conventions your application will fill the whole desktop application area automatically. If you wish it does not do that then I suggest you read the tutorials because I'm not so sure what you should do in that case.