New iPhone to have 960×640 Resolution
According to Digitimes Research, the new iPhone, dubbed the iPhone 4G, will have a much higher screen resolution
The new device will adopt IPS in-plane switching panels with FFS fringe-field switching technology and a 960×640 resolution, Kuo said, noting that LG Display and Prime View International are the panel suppliers.
Compare the new iPhone's 960 by 640 resolution to the iPad's 1024 by 768 resolution.
9.7-inch (diagonal) LED-backlit glossy widescreen Multi-Touch display with IPS technology
1024-by-768-pixel resolution at 132 pixels per inch (ppi)
Why Apple didn't maintain the same aspect ratio between the devices is beyond my understanding. Both the iPhone & iPad will be running the same apps so I think it would be much easier if the resolutions scaled properly. Of course, that is not the case. So it looks like we will still have some incompatibilities between the two devices for the foreseeable future. Take a look for yourself:

