I feel 100% spoiled by the iPhone's PPI.
It's undeniably unequivocal. After owning the 1st iPad for 6 months, and acquiring the iPhone 4, the difference was just unbearable for me. The iPad has been sold since the discovery, and I am iPad-less. I do plan on an iPad 2, but only because it is thinner and lighter which does tilt the scales back towards being more balanced.
I found myself wanting to use the iPhone 4, despite the smaller screen, versus the iPad; therefore, I will accept the iPad 2 as it is now and patiently wait for a higher resolution.